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Permit MI98-0131 - PACIFIC VIEW OFFICE PARK - RETIANING WALL
PC(LiP View of*.k. ft#11 ('443/ City of Tukwila (206) 431 -3670 Community Development / Public Works • 6300 Southcenter Boulevard, Suite 100 • Tukwila, Washington 98188 MISCELLANEOUS PERMIT WARNING: IF CONSTRUCTION BEGINS BEFORE APPEAL PERIOD EXPIRES, APPLICANT IS PROCEEDING AT THEIR OWN RISK. Parcel No: 092304 -9367 Address: 12421 PACIFIC HY S Suite No: Location: BUILDING A Category: OTHR ' Type: MISCPERM Zoning: C /LI KR314E SEC923 Const Type: Gas /Elec.: Units: 000 Setbacks: North: Water: 125 Wetlands: Permit No: Status: Issued: Expires: MI98 -0131 ISSUED 08/07/1998 02/03/1999 Occupancy: UBC: 1997 Fire Protection: N/A .0 South: .0 East: .0 West: .0 Sewer: RAINIER VI Slopes: Y Streams: Contractor License No: SABEYC *141PH OCCUPANT PACIFIC VIEW OFFICE PARK 12421 PACIFIC HY S, TUKWILA WA 98168 OWNER WELCH JOHN T Phone: (206)000 -0000 12421 PACIFIC HIGHWAY S, SEATTLE WA 98168 CONTACT HAYNES LUND Phone: 206 281 -8700 101 ELLIOTT AV W SUITE 330, SEATTLE WA 98119 PROJECT PACIFIC VIEW OFFICE PARK 12421 PACIFIC HY S, TUKWILA WA 98168 ENGINEER NELSON - BOURDAGES Phone: 425 827 -5995 512 SIXTH ST S SUITE 202, KIRKLAND WA 98033 CONTRACTOR SABEY CONSTRUCTION INC. Phone: 206 281 -8700 101 ELLIOTT AVENUE WEST #330, SEATTLE, WA 98119 **************************************************** * * * * * ** * * * * * ** * * * * * * * * * * ** * * * ** Permit Description: CONSTRUCTION OF CONCRETE RETAINING WALL FOR BUILDING "A' OF PACIFIC VIEW OFFICE PARK SITE. ** k************************************************* * * * * * * * * * * * * * * * * * * * ** * * * * * * * *** Construction Valuation: $ 150,000.00 PUBLIC WORKS PERMITS: *(Water Meter Permits Listed Separate) Eng. Appr: Curb Cut /Access /Sidewalk /CSS: N Fire Loop Hydrant: N No: Size(in): .00 Flood Control Zone: N Hauling: N Start Time: End Time: Land Altering: N Cut: Fill: Landscape Irrigation: N Moving Oversized Load: N Start Time: End Time: Sanitary Side Sewer: N No: Sewer Main Extension: N Private: N Public: N Storm Drainage: N Street Use: N Water Main Extension: N Private: N Public: N **************************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** TOTAL DEVELOPMENT PERMIT FEES: $ 1,880.96 ************* * * * * * * * ** * * * * * * * * * * * * * * * * * * * * * * *tik * * * ** *fir * * * * * * * * * ** * * * * * * * * * * * * * ** Permit Center Authorized Signature: Date: R'`.7 -7F I hereby certify that I have read and examined this permit and know the sane to be true and correct. All provisions of law and ordinances governing this work will be complied with, whether specified herein or not. The granting of this permit does not presume to give authority to violate or cancel the provision of any other state or local laws regulating construction or the performance o work. I,am authorized to sign for and obtain this development per Signature: Print Name: _ As-a.) Date: ! AGic -9 D This permit shall become null and void if the work is not commenced within 180 days from the date of issuance, or if the work is suspended or abandoned for a period of 180 days from the last inspection. CITY OF TUKWILA Permit Cent& 6300 Sout(tcenter Boulevard, Suite 100 Tukwila, WA 98188 (206) 431 -3670 • R STAFF USE ONLY Project Number: . e° (0 Permit Number: M.h 4113•013 .1 Miscellaneous Permit Application Application and plans must be complete in order to be accepted for plan review. Applications will not be accepted through the mail or facsimile. P¢ro act Name/Tanc. aVinl: �•1�tgy.i C�FFIGEi FA,R.1c Description of work to be done: co i t�-r -. N1Ai WA4.zs - P (4 i c i Q9 A Will there be storage of flammable /combustible hazardous material in the building? ❑ yes ❑ no Attach list of materials and stora.e location on se•arate 8 1/2 X 11 •a•er indicatin• • uantities & Material Safet Data Sheets Value of Construction: *1504000.00 Tax'�Parcel Number-: O` V304'1')07'est :WM471" ""10g'I"°4 Site Address: 2421 TGIFic 4-11 Witt %. City Stale/Zip: Ttn wltdkNV9ib8e� , Property Owner: 301-Ht■ WEU,“ Phone: Phone: 206) - ?e} 2 - 55 04 Street Addrec • 12421 1�ut =fc 1.11ort< --►wry So. _1 City State/Zip: IvicwlIA. Ala Cob Fax it: ZoCe - ?A Co- 2234 C•ntact . Person: •• 1- 4.J/JD ,el-t '( n OW° • 1\V N Phone: 20% " Z :. 1 .i"1 Cad Street Address: t 01 gu-Larr W, &ut!r e 550 SE City State /Zip: t /A946119 Fax #: 20fo - Z. 1?7� ow) Contractor: cfaJW C.Q0S- 4- aA3C110.3 1 hr— Phone: Zo(> - 2,P,t — 41.200 Street Address: . City SA At 9 Fax #: Zap ' 281 + 0°120 Architect: 1 beer H611 4110 CHt'1ra'c rs 1 Phone: s%? v- 821- 2100 Street Addre s: 10• • k 3 F'u Srsf - WZ. w_ City Sta - /Zip: . s , : •;,.,,, Fax #: 5- W. : a:.- - Irgiis.neer: — �Ot>'It� Phone: 64-Z5- 827 - 5gA 5 Fax #: .425- 5 - 4∎550 Street Address: S �r 2070 512 S1xrH &Ma ti So IggoA City State/Zip: K MISCELLANEOUS PERMIT REVIEW AND APPROVAL REQUESTED: (TO BE FILLED OUT BYAPPLICANT)'.' Description of work to be done: co i t�-r -. N1Ai WA4.zs - P (4 i c i Q9 A Will there be storage of flammable /combustible hazardous material in the building? ❑ yes ❑ no Attach list of materials and stora.e location on se•arate 8 1/2 X 11 •a•er indicatin• • uantities & Material Safet Data Sheets ■ Above Ground Tanks ■ Antennas /Satellite Dishes ■ Bulkhead /Docks ■ Commercial Reroof ❑ Demolition ❑ Fence ❑ Mechanical ❑ Manufactured Housing - Replacement only ❑ Parking Lots reelaining Walls ❑ Temporary Pedestrian Protection /Exit Systems ❑ Temporary Facilities ❑ Tree Cutting ' APPL'ICANT,REQUEST.FOR MISCELLANEOUSTUBLIC >WORKS.PERMITS'?.':'' ❑ Channelization /Striping ❑ Flood Control Zone ❑ Landscape Irrigation ❑ Storm Drainage ❑ Water Meter /Exempt # ❑ Water Meter /Permanent # ❑ Water Meter Temp # ❑ Miscellaneous ❑ Curb cut/Access /Sidewalk ❑ Fire Loop /Hydrant (main to vault) #: Size(s): ❑ Land Altering: 0 Cut cubic yards 0 Fill cubic yards 0 sq. ft.grading /clearing ❑ Sanitary Side Sewer it: ❑ Sewer Main Extension 0 Private 0 Public ❑ Street Use ❑ Water Main Extension 0 Private 0 Public 0 Deduct 0 Water Only Size(s): Size(s): Size(s): Est. quantity: gal Schedule: ❑ Moving Oversized Load/Hauling MONTHLY SERVICE BILLINGS TO: " >;. Name: Phone: Address: City /State /Zip: 0 Water 0 Sower 0•Metro 0 Standby WATER METER DEPOSIT /REFUND BILLING: Name: Phone: Address: City /State /Zip: Value of Construction - In all cases, a value of construction amount should be entered by the applicant. This figure will be reviewed and is subject to possible revision by the Permit Center to comply with current fee schedules. Expiration of Plan Review - Applications for which no permit is issued within 180 days following the date of application shall expire by limitation. The building official may extend the time for action by the applicant for a period not exceeding 180 days upon written request by the applicant as defined in Section 107.4 of the Uniform Building Code (current edition). No application shall be extended more than once. Data applicatio1eptd: fi6 Data application a� s� Appliale: (initials) ALL MISCELLANEOUS PERMIT APPLICATIONS MUST BE SUB _ _ TED WITH THE FOLLOWING: ➢nr, ` At:L,., VItI AL dE AT A LEGIBLE SCALE AND NE /6 LY DRAWN , 011Iugl '' aTI PLANS AND UTILITY PLANS ARE TO BE COMBINED .4 ARCHITECTURAL DRAWINGS REQUIRE STAMP BY WASHINGTON LICENSED ARCHITECT STRUCTURAL CALCULATIONS AND DRAWINGS REQUIRE STAMP BY WASHINGTON LICENSED STRUCTURAL ENGINEER CIVIUSITE PLAN DRAWINGS REQUIRE STAMP BY WASHINGTON LICENSED CIVIL ENGINEER (P.E.) r SUBMIT APPLICATION AND REQUIRED CHECKLISTS FOR PERMIT REVIEW Submit checklist No: M -9 Above Ground Tanks/Water.Tanks - Supported directly upon grade exceeding 5,000 gallons and a ratio of height to diameter or width which exceeds 2:1 In Antennas /Satellite Dishes . Submit checklist No: M -1 71 Awnings/Canopies -. No signage Commercial Tenant Improvement Permit O Bulkhead /Dock : ; Submit checklist No: M -10 0 Commercial :Reroof' " Submit checklist No: M -6 in Demolition. Submit checklist. No: M -3, . M -3a 73 Fences - Over 6 feet in Height Submit checklist No: M -9 0 Land Altering /Grading /Preloads Submit checklist No: M -2 El Loading Docks Commercial .Tenant Improvement Permit..; Submit checklist No: H -17 El Mechanical (Residential & Commercial) Submit checklist No M -8,: Residential only = H -6, H -16 0 Miscellaneous; Public,Works Permits . ' . Submit checklist' No H -9 0 Manufactured Housing-(RED INSIGNIA ONLY :' Submit checklist . No: ..M 5 0 Moving Oversized: Load /Hauling • ' Submit. checklist No: M -5 Parking Lots Submit checklist No: M -4 Residential Reroof -: Exempt with following exception! If roof structure to be repaired or. replaced Residential Building Permit Submit checklist • No: M -6 " Retaining Walls - Over 4 feet in height Submit checklist No: M -1 I J Temporary Facilities Submit checklist No: M -7 fJ TemporaryPedestrian Protection/Exit Systems' Submit checklist No:. M -4 0 Tree Cutting Submit checklist No: M -2 • Q Copy of Washington State Department of Labor and Industries Valid Contractor's License. If not available at the time of application, a copy of this license will be required before the permit is issued, unless the homeowner will be the builder OR submit Form H -4, "Affidavit in Lieu of Contractor Registration ". Bullding;Owner /Authorized Agent If the applicant is other than the owner, registered architect/engineer,,or contractor licensed by the State of Washington, a notarized letter from the property... owner authorizing the agent to submit . this permit application and obtain the permit will be required as part Of this submittal. I HEREBY CERTIFY THAT I HAVE READ AND EXAMINED THIS APPLICATION AND KNOW THE SAME TO BE TRUE UNDER PENALTY OF PERJURY BY THE LAWS OF THE STATE OF WASHINGTON, AND I AM AUTHORIZED TO APPLY FOR THIS PERMIT. Signature :,-. BUILDING OR AUTHORIZED, er.7„-ii_i." Print name: 4-JAWS' L-vaa Date: 1 Ju Lam`( e, Phone :t04_281°87001 Fax #: go4,_281-co7Lc Address: soave C _p 1O E.444 arri (E W awre 3�0 MISCPMT.D k City /State /ZIP: • T T cte) 119 Iksw Pddr:es .: 12421 PACIFIC HY S Suite: Tenant: Type: MISCP'ERM P r'ce l,. # :. 092304-9367 :. CITY OF TUKWILA ? * •k k -k -k •k 'k k *''k * * * :k 'k •k * -k 'k •k 'k •k 'k' 'k 'k •k 'k tk •k •k *4 '•k ak, k 4 4 * -k, * 'k * -k •k k * 'k 'k 'k 'k *'k •k4i* 'k -k -k 'k 't4. k 'k `k k •k •k •k . k 'k *14. k k k -k k Per;mi.t Cond i t ions :: • 1 . Temporary erosion .control measures shall' 'ba '. implemented as the t li-st order, crt, 0 US ine..y tc� pr ,v ,tit sediMent0ei96 otf,{ "ite..or. into' ex is t:i.nia ;.'j,tt- 6.iii'K� ' 1.a' e,§.4; `jn; ties-. 4 Na° t1 Na :chances w i 1.1 ber. n 1e' Ec...the pie t •tin $. : ' t�e�ov, cts b.Tr L Archi test or Eng iyee.r and .the<.Tuhcp,,i 1a .Bu rit'1i4r1 k� R:;"; ':1,:O �. .• .+. • r , ,.,. r yr i`ig4'.n" °•A'1. Al 1 perm is:, 1Jo,s"Dect,.io.n �reoarda,r i:4n;i�i a�x.� i.tt• d'i j: ' :MS.:.. $Ita.l 1 . h�'e ,ava i 1 ab i • e . tike i�ob site 'z;pr i or to the ty l;a ‘..'"'i,',' ; b Y anlr;,don- 5,truct1on F.he &e,;docurnents are., to he rna ;ntaine i a c,,.,av,ii 1 able :urlti,l„ fiina'1 i'nS )act,ioil �aupr.6vefi 1 n.ar~an;t'0. fi{ ,!'` ,�': 4. Al 1 construction f : :tr • b.e. done ,i n,', c.o•nfornrance ,�.ri th � app aved, . p la ny..aiyti: r eaui r� ements oft thevCiii.i f•.or�m Bu i 1 d'ilnp: Code ,1.1 994 :Edition :' a: amended, Uniftio.r n Methanica1 Code t1994,s�E "deti6f ��.nd tWfrdshinuton State h;errgv, :Code ,(1}994 Edition) .,„ - ub+�ra�de re,per anon tnc1udino..,.dr ainaae, e'KCivat"ion „, �r „x co mu ,ettorl, and • fi.11 reOuirenrent �$ha'11 conrornt st4�.�ictls wit a raccinfinendatt.ii or)'s ?l i ven .i'ri t•h "e.'tso i 1 s;�•'repor t. - � ,Va 1f.i'd i t •oi . Per-mi t. Tire,; i VI �u`ance 'ofT'a- '',per rni t or are;.lrovai1 p1 #1 -4 , suecit "ica.ti:onst' °'an'dfomp" atiOr}s..Msh'a11 not he si}n- ! env .yro'laton t ft.,:, i „,,to,,,,, e a' :,per•rni t t” , , � , an 1 ., ^4 vat ii. y ' .'t any of ,the, pr 0vAlSior S',':'.0 ti, .b'uilldini co:de,.,or ofiitanv ' 4' : utbei•. ordinance ot,.�th.a' fur 1$d•1 t.': o�r� ' N ? rri t� pr esumin9 too 9.i4'ep author it,� totJvi'olate r arlcal', the'A.rOV'ia. ion. i'f,,,,thi,., ;., x:, c odes= ,ha.1Jfl, rhestiva i i :d' 'R: •�` ' �+ 4 fj1 �F r ^i M1 krj �F }. 3i . 'i pCa i 7 Per nri t No: MI96 -0131 Status: ISSUE :) `' Wnp l i ed: 07/1.4",(1998 I ,suedi :.1. 08/071 1 998 CITY OF TUKWILA Department of Community Development Building Division- Permit Center 6300 Southcenter Boulevard, Tukwila, WA 98188 Telephone: (206) 431 -3670 REVISION SUBMITTAL DATE: Zv Ju c.•x^ ct v PLAN CHECK/PERMIT NUMBER: )14192) • 01 'J J PROJECT NAME: arc-4 rzttics V i r w OFF t c,e PROJECT ADDRESS: 1 i4 2.9 C 1-1 Lat-LLQft r SOU 71.4 CONTACT PERSON: L:86-C,/s A PHONE: QOC • 247 - %0C� REVISION SUMMARY: CHs - rJJCTeS i J TZECSPOcJ3ZZ -TO StRO c.zuRdec'Cs lo....1171. Ink 4 _• kJ L! —' SHEET NUMBER(S) i 1 "Cloud" or highlight all areas of revisions and date revisions. SUBMITTED TO: CITY USE ONLY PLAN REVIEW /ROUTING SLIP ACTIVITY NUMBER: PROJECT NAME: XOriginal Plan Submittal Response to Correction Letter # Mlqs-oS( DATE: '7-1- Qe1 Pc \Hew Offite Park N l� fin cn3 - Ricig Response to Incomplete Letter Revision After Permit Is Issued. DEPARTMENTS: Bull g Division rE Iic Work stile IL 1-16-C1 Fir'lvention j( Structtr I 06f Plani�ira� Division Permit oordinator DETERMINATION OF COMPLETENESS: (Tues, Thurs) Complete ❑ Comments: Incomplete DUE DATE: Not Applicable ❑ TUES /THURS ROUTING: Routed by Staff Please Route ❑ No further Review Required (if routed by staff, make copy to master file and enter into Sierra) REVIEWERS INITIALS: DATE: APPROVALS OR CORRECTIONS: (ten days) Approved ❑ Approved with Conditions ❑ REVIEWERS INITIALS: DUE DATE: 8'-/ - -/ CJ Not Approved (attach comments) ❑ DATE: CORRECTION DETERMINATION: Approved Approved with Conditions ❑ DUE DATE: Not Approved (attach comments) ❑ REVIEWERS INITIALS: DATE: \PR•ROUTE.UOC 6/98 ....• ". •..•. ' Retain a copy with permit INSPECTION RECORD INSPECTION NO. CITY OF TUKWILA BUILDING DIVISION 6300 Southcenter Blvd, #100, Tukwila, WA 98188 PERMIT NO. (206)431-3670 )71<proved per applicable codes. J Corrections required prior to approval. COMMENTS: ccaece-c7 p+rs .plearar- Jr-4,4c. 667e ieez,-,70:6") InsteerAif Date:5//0/6 El $47.00 REINSPECTION FEE REQUIRED. Prior to inspection, fee must be paid at 6300 Southcenter Blvd., Suite 100. Call to schedule reinspection. I Receipt No 1 Date: INSIi.ECTiO RECORD. Retain a `copy with permit CITY OF TUKWILA BUILDING DIVISION 6300 Southcenter Blvd., #100,' Tukwila, WA 98188 (206) 431 -3670 Project:, .../ r n �/ �� ' r Type of inspec G- ri,c�i_e�f' pa, r Addres .// 7 (���f �' Date called: Special Instructions: q*er / (4i'r Date wanted: q i .m. Requester: 1 Phone . zen, z vo Approved per applicable codes. Corrections required prior,to approval. COMMENTS: Inspector / / $42.00 REINSPECTION Fi REQ'IRED.. Prior to inspection, fee must be paid at 6300 Southcenter Blvd., Suite 100, Call to schedule reinspection. Date: 2,0 INSPECTION NO. ---mrpprmvro.00-vw-;.-4,t -INSPeCTION RECORD Retain a copy with permit CITY OF TUKWILA BUILDING DIVISION 6300 Southcenter Blvd., #100; Tukwila, WA 98188, PERMIT NO. (206) 431-3670 Proje. , .f. • . ,,,_ .2., e , Type ofpoctiorl: • , aiediz. CI Address: 1 i g Il'ae Date called: 9 z. Date wanted: 9/3te" p, m. - Spec al instructions' Cfl 30 - at r- 4;e2eC/4( "tilea-ne>1 ci Requester:7. -1 Phone No • 010 C,-..c: Li 7 zcl a Approved per applicable codes. Corrections required prior to approval. " COMMENTS:• e_.(4 -c„ ,-/Ar_s,op 07( s/725,. /3 6...g4 ire,e :•: $42.00 REINSPECTION FEE REQUIRED. Prior to inspection, fee must be paid at 6300 Southcenter Blvd., Suite 100. Call to schedule reinspectiOn. INSPECTION NO. ktTin�Rra�nrir. M'+, f+.+ �k+ trwr: �y ,:�`'ttbw%e"+rAw!p„+�a'7.«ww^: i ; INSPECTION RECORD Retain a copy with permit CITY OF TUKWILA BUILDING DIVISION 6300 Southcenter Blvd., #100,' Tukwila, WA 98188 617-0(3/ PERMIT NO. ?06) 431 -3670 Project: _ ( , l ' Type of inspe tio /''�.�_� ` fib t Address: n - / z-tfz1 �a �-_c Date called: f aft Special instructions: iqpm �,L . taki -- Pee C U ! BO Date wanted: ! . . Requester: Phone N 66' 2 E//— g2 5e() Approved per applicable codes, Corrections required prior to approval. COMMENTS'"' Inspector. Date: 1-1 $42.00 REINSPECTION FEE REQUIRED. Prior to inspection, fee must be paid at 6300 Southcenter Blvd., Suite 100. CaII to schedule reinspection. : ?''�:.n+•w a - e> rwi.¢, F�{,;: 1z44io�Mrzrfea+ vw+.. w�uw..:. x,+...; w:._....,.,.....,.—.,.. Q........,, ...., ....................,,,,.r / C; INSPECTION RECORD Retain a copy with permit INSPECTION NO. CITY OF TUKWILA BUILDING DIVISION 6300 Southcenter Blvd., #100,' Tukwila, WA 98188 C`, -013 PERMIT NO. .(206) 431 -3670 Project: - Q G e_ Type of inspection4 n 4Z,rr c- P( N Address: AZ 1/c2/ ac. Date called: �-.2.V Special instructions: � - AO-5a2' f % � W/ • /"P ` Date wanted: am. �Z m. Requester: Phone No. ,2 64-,2 //- E 2 V Approved per applicable codes. [Corrections required prior to approval. COMMENTS: ot: ( 4 e2 �Goo,— lnspector,/ l Date: $42,00 REINSPECTION FEE REQUIRED. Prior to inspection, fee must, be paid at 6300 Southcenter Blvd., Suite 100. Cali to schedule reinspection. 4.11.77rrir , * Is 7.4 * •A-1c)i tir * trA * 1r * A. A * * * * It * •A'..k A * T.,T Y Wf-1 • . • . • . . 'IR '119700809 'Amount: • • • 1-1,4:1:i.'75. 0E3/07Pii8:;11.:59 Ps.),,merit; Method ,t 1142 • Notatiori.1 ,pAril.T.Y CORP Init,:. .T1(7,f, Permit Not MI96-0131 Type: ,MISC13,61lIal ',14ISCEI.J..141411:0116,:,PlE1114IT ,, ',',, ' Parcel No 092304-9367 Site Address,: 12421, l'C11:*IC 14Y, 6 Lac S.C1 tin:, 61.1ILL)3Na..0 , • - - ,,,, . .• : 'rot al Fees t - -.1i...860.96 Thts'Paymenti 1,141..;75 . Totztl ALL. frots.i..C. - '1", 0,0' 1 iciricleA•k*:.)1/4•AlvsC.**********-A*A*141;0.A.1411,';*.ivit4rIl4$10ti.;k1t*It'lv**kirl'FY. ..: -*••• ACcount, qade: . pt �n ..: . .. : :Arkpant : ,•,... 000/322.100 , i3t.III..1)INCi --,. NoNREs. . ,:-, . '.1,, 1 372!:.:). . . • . . , ' 000/386'.904 -. STATE '13UILIYE,140 61112CIIIIR6E,;:‘,- .-, = ... -,.. '4..;59,:.- ..,......., „,.... ... .. ...:. - , .. - - - -... ....... ,...... ..,............. 7-1- ......... ..: ;................:-........:- - :....:.... - :, ......"....., , r .... -.:.,, : . • akt1 *it #t\ **10•k0k *A *•4, *AA :4A *A . kf********A* ttst* kA* k *t4 ** * *:1AA*k * *Azti +);l'* CITY OF TUKWIL A. WA TRAWSM:( 1 A•ko1**** ** 4i%** *A.*** ** ** * * *t! **tt*t%***A**'.i * *f•*A•slA• *a'* 4,14A*4*k**:Ak** TRANSMIT Number: 8900801 Amount 739 „21 0?/27/98 11;58 Payment Mrthvda Notation: 'nit:: permit Mu MI98 -01 ►i. Tvr.'ec M18CPERM ,023CEL.LnMEOl1 PCRM3 T ar oe l No: 092304-9367. Site r4ddr'esR: 12421 PACIFIC HY 8: . Location; BUILDING A Tota i FPe 1 n f38n.G . Tri i a._f'�ivmerit 739.21 Total ALL Pmt 719:21 • 33alance: 1, t41.7S Att•k•kAfiIvi,,* A ** *fi>tzl�A * * *At ***7.,** AA,• ktlt4* Ii*k.A.s1 **kA{t34.s44,:4 *k *** *'* *trap *1*. Acgou'il t, Code Deaor'iotion {amount, .00Q/34 ..830 PLAN CHECK 7 FlONRE:i 711 21 May 5, 2000 City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director Haynes Lund 101 Elliot Ave W Suite 330 Seattle Wa 98168 RE: Permit Status MI98 -0131 12421 Pacific Hwy S Dear Mr Lund: In reviewing our current permit files, it appears that your permit to construct a concrete retaining wall for building A, issued on August 7, 1998, has not received a final inspection as of the date of this letter by the City of Tukwila Building Division. Per the Uniform Building Code and /or Uniform Mechanical Code, every permit issued by the building official under the provision of this code shall expire by limitation and become null and void if the building or work authorized by such permit is not commenced within 180 days from the date of such permit, or if the building or work authorized by such permit is suspended or abandoned at any time after the work is commenced for a period of 180 days. Based on the above, if a final inspection is not called for within ten (10) business days from the date of this letter, the Permit Center will close your file and the work completed to date will be considered non - complying and not in conformance with the Uniform Building Code and/or Mechanical Code. Please contact the Permit Center at (206)433 -7165 if you wish to schedule a final inspection. Thank you for your cooperation in this matter. Sincerely, ;3Lk Bill Rambo Permit Technician Xc: Permit File No. M198 -0131 Duane Griffin, Building Official 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 AGRA ENGINEERING GLOBAL SOLUTIONS June 11, 1999 8 -91 M- 12475 -0 Sabey Construction 101 Elliott Avenue E., Suite 400 Seattle, Washington 98119 -4220 Attention: Mr. Mark Velasquez, Project Engineer AGRA Earth & Environmental, Inc. 11335 NE 122nd Way Suite 100 Kirkland, Washington USA 98034 -6918 Tel (425) 820-4669 Fax (425) 821 -3914 Subject: Revised Summary of UBC Special Inspection and Materials Testing Services 1. City of Tukwila Permit Number: D98 -0214 (Building "A ") 2. City of Tukwila Permit Number: D -98 -0321 (Annex) 3. City of Tukwila Permit Number: MI98 -0131 (Retaining Wall for Building "A ") International Gateway Corporate Park — Building "A ", Annex 12301 Tukwila International Boulevard Tukwila, Washington Dear Mr. Velasquez: AGRA Earth & Environmental, Inc. (AGRA) respectfully submits this letter as our final summary of UBC special inspections and materials testing for the above - referenced project. AGRA performed inspections for this project beginning on August 22, 1998 through May 24, 1999 as requested and scheduled by representatives of Sabey Construction. Daily field reports were prepared and distributed at the time our services were provided. These reports form the basis for this final summary of our inspections. In accordance with the City approved plans and the request and authorization of Sabey Construction, AGRA performed inspections for the following: 1. Reinforcing steel inspection for the structural concrete; 2. Concrete placement inspection and testing for the structural concrete; 4. Shotcrete inspection and testing; 5. Spray - applied fireproofing inspection and testing; 6. Epoxied anchor bolts; 7. Visual and ultrasonic inspection of structural steel welds for the field welding and fabrication shop; and 8. Reinforcement and Grouting inspection and testing for the soldier piles and auger cast piles. S1WORDPROC198 Projects \Seattle \12000x112475 \Revised final leller.wpd Sabey Construction June 11, 1999 8-91M-12475-0 Page 2 In our opinion, the work which was inspected as referenced in our daily field reports was performed in general conformance with the approved plans and specifications. If you have questions or desire additional information, please call at your convenience. Sincerely, Timothy Associat en S. Sahi, P.E. WABO Technical Director TR H/KSS/jdp cc: City of Tukwila Sabey Construction EXPIRES 12/18/ Fax: 206-24178223 S;IWORDPROC■98 Projects\ Seattle \12000s12475\Revisedfinal Ieller,w Reid iddleton July 22, 1998 File No. 24 -98- 022 - 008 -01 Mr. Duane Griffin, Building Official City of Tukwila 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 Subject: Building Permit Plan Review - First Submittal Pacific View Office Park - Retaining Walls (MI98 -0131) Dear Mr. Griffin: We reviewed information for the proposed project for compliance with the structural provisions of the 1994 Edition of the Uniform Building Code as adopted and amended by the City of Tukwila. The following comments should be addressed: 1. The General Notes indicate that the 1997 UBC was used in design; however, the General Conditions, Item 14, refers to the 1994 Edition of the UBC. Please clarify. 2. The Foundations section of the General Notes references the soils report dated March 16, 1998, with a memo dated May 18, 1998. The memo, by Geotech Consultants, dated June 9, 1998, should also be included in the General Notes. 3. There should be a note stating that imported, free draining material is to be used on site, as indicated in Geotech Consultants, Inc. memo, dated June 9, 1998, Scenario 2. 4. A footing bearing pressure of 4760 psf is calculated on page 1 However, Detail 13/R2 shows these footings bearing on structural fill. The allowable bearing pressure recommended for this condition by Geotech Consultants, Inc. is 3000 psf, unless lean concrete is used. 5. It appears the retaining walls are designed for an active soil pressure of 40 pcf. The walls appear to be restrained at the top and should, therefore, be designed for an active soil pressure of 55 pcf as recommended in the soils reports. A more detailed review will be performed following receipt of the revised calculations. Engineers Planners Surveyors Reid Middleton, Inc. 728 134th Street SW Suite 200 Everett, Washington 98204 Ph: .425 741.3800 Fax: 425 741.3900 Mr. Duane Griffin, Builing Official City of Tukwila July 22, 1998 File No. 24 -98- 022 - 008 -01 Page 2 The review comments listed above should be responded in itemized letter form. We recommend that the permit applicant have the Structural Engineer of Record, Nelson- Bourdages, respond to the above comments and resubmit two copies of revised drawings and one copy of supplemental structural calculations directly to our office. A copy of this letter has been forwarded to the architect, Freiheit & Mo architects Inc., and the project contact, Sabey Construction, Inc., for your convenience. Please note that corrections or comments made during the review process do not relieve the project applicant or designer from compliance with requirements of codes, conditions of approval, and permit requirements; nor is the designer relieved of responsibility for a complete design in accordance with the laws of the state of Washington. This plan review check is for general compliance with the Uniform Building Code as it relates to the project. If you have any questions or require any additional clarification, please call. Sincerely, Reid Middleton, Inc. Da 'd B. Svianson, P.E. Pro ct Manager Ferron P. Smith, E.I.T. Plan Review Engineer bj? wt\p lanrevw \tukwila\98\t008r1.docVps cc: Mr. Haynes Lund, Sabey Contractors, Inc. Freiheit & Mo Architects, Inc. (fax) Reid iddleton July 30, 1997 File No. 24 -98- 022 - 008 -02 Mr. Duane Griffin City of Tukwila 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 Subject: Building Permit Plan Review - Final Submittal Pacific View Office Park - Retaining Walls (MI98 -0131) `,) RECEIVED JUL 3 1 1998 COMMUNVi Y - DEVELOPMENI Dear Mr. Griffin: We reviewed information for the proposed project for compliance with the structural provisions of the 1994 Edition of the Uniform Building Code as amended and adopted by the City of Tukwila. It appears the applicant has responded successfully to our previous review letter, dated July 22, 1998. Therefore, we have no additional comments. Enclosed are the drawings, structural calculations, geotechnical report, and correspondence from the engineer for your records. We forwarded a copy of this letter to the architect, Freiheit & Mo architects Inc., and the project contact, Sabey Construction, Inc., for your convenience. If you have any questions or require any additional clarification or information, please call. Sincerely, Reid Middleton, Inc. David B. Swanson, P.E. Project Manager vlf\wt\p1a evw\lukwila\98\t008r2.doc\jbf Enclosures cc: Mr. Haynes Lund, Sabey Contractors, Inc. Freiheit & Mo Architects, Inc. (fax) Ky le K. Y atsuka, E.I.T. Pla Revie Engineer clrY of ruKwu JUL 3 1 1998 PERMIT CENr'ER Engineers Planneri Surveyors Reid Middleton, Inc, 728 134th Street SW Suite 200 Everett, Washington 98204 I'h:. 42S 741 -3800 Fax; 425 741.3900 July 15, 1998 21- -ooz —6 ) City of Tukwila Department of Community Development Dave Swanson, P.E. Reid Middleton 728 - 134th Street SW, Suite 200 Everett, WA 98204 RE: Structural Review Pacific View Office Park - Keystone Walls (M198-0130), Pacific View Office Park - Retaining Walls (MI98-0131), Pacific View Office Park - Shoring Walls (MI98-0132) Dear Mr. Swanson: John W. Rants, Mayor Steve Lancaster, Director Please review the enclosed plans and documents for structural compliance with the 1994 Uniform Building Code. If you should have any questions, please feel free to contact me at 206-431-3671. Sincerely, (4/1-tahA- Brenda Holt Permit Technician encl xc: MI98-0130 MI98-0131 MI98-0132 6300 Southcenter Boulevare4 Suite #100 Tukwila, Washington 98188 • (200 431-3070 , • (206)4314, ' " " �S�}3H;Y (X)1111()114: 11A P1;1: 1-I E•_ - I.'F;E TO: RE: SAGE )RPORATION ARCHITECTURE GROUP 101 EL ;:ITT AVE. WEST, SUITE 330 SEATTLE, WA 98119 PHONE: 2061281 -8700 FAX: 206 - 281.0920 - 61Z-G22 - oorc -oz RECEIVES) joi TRANSMITTAL COVER SHEET DAVID SWANSON Reid Middleton, Inc. 728134th Street SW Suite 200 Everett, WA 98204 MISCELLANEOUS PERMIT MI98 -0131 DATE: 07/28/98 4'13 .J PROJECT 0: 98 -70 -22 PROJECT: Pacific View Office Park z(- rA " " "" WE ARE SENDING YOU: THE FOLLOWING ITEMS: IxJ X ATTACHED UNDER SEPARATE COVER PRINTS ORIGINALS n VIA OVERNIGHT VIA COURIER n SUBMITTALS n SAMPLES VIA MAIL I n l V• IA HAND DELIVERY El L• ETTER DOCUMENTS FOR YOUR: INFORMATION AND USE APPROVAL I x I REVIEW AND COMMENT n AS REQUESTED FOR SIGNATURE AND RETURN n N• O ACTION REQUIRED it 4 I :,If I 07/27/98 ■ i fi .r1 Building A Retaining Walls Sheet R1 (revised) 1 07/27/98 Letter responding to Review Comments NOTE: IF ENCLOSURES ARE NOT AS NOTED, KINDLY NOTIFY US AT ONCE. REMARKS: BY: CC: TMITTUKW.WK4 JIa f,ne3 oCund File c :J 1 Wj si?t32) • • July 27, 1998 Mr. Duane Griffin, Building Official City of Tukwila 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 Subject: Building Permit Plan Review Pacific View Office Park Retaining Walls (M198 -0131) Dear Mr. Griffin: RECEIVED This letter addresses the plan checker's comments with regard to the retaining wall design for the aforementioned project. 1. The typographical error in Item 14 of the General Notes is corrected to be 1997 Edition of the UBC. 2. The memo, by Geotech Consultants, dated June 9, 1998, is referred in the revised General Notes. 3. Backfill free draining material is used for the retaining wall per Geotech's report. This requirement is shown in Detail 13/R2 in the original submittal. 4. The allowable bearing pressure is 5,000 psf for the footing supported on lean concrete per Geotech's report. This information is shown in Detail 13/R2. 5. The retaining wall was designed against an active soil pressure of 40 psf for the yielding condition before the floor slabs are cast, and designed against an active soil pressure of 55 psf for the unyielding condition after the floor slabs are cast, per Geotech's report. If you have any questions or require any additional clarifications, please call. Sincerely, L. Charlie Cao, Ph.D., P.E. Project Engineer cc: Mr. Haynes Lund, Sabey Construction NELSON- BOURDAGES a Division of Poggemeyer Design Group, Inc, 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827 -5995 • Fax (425) 828 -4850 GEOTECH CONSULTANTS, INC. 13256 NE 20`h Street, Suite 16 Bellevue, WA 98005 (425) 747 -5618 FAX 747 -8561 1Il O JN: 98063 To Haynes Lund Fivrs Marc R. McGinnis Company Sabey Corporation Date: June 9, 1998 Address: 101 Elliott Avenue West, Suite 330 FAX: (206) 281 -0920 Seattle, Washington 98119 -4220 Phone: (208)281 -4200 RE Additional Considerations for Wall and Foundation Design Pacific View Office Park Tukwila, Washington RECEIVED CITY OF TUKWILA U ;U ; 6 1998 PERMfT CENTER -J � ;::J • This memo is an addendum to our March 18, 1998 geotechnical engineering study. The following items am addressed by this addendum: • Reuse of an -site soils as structural fill. • Recommended foundation types for the three buildings following the recently - conducted supplemental test pits. • Design parameters and backfill considerations for the permanent building walls. As we have discussed in our meetings, the an -site soils could be reused as structural fill on a very limited basis. The fine- grained silt soils, which will constitute most of the excavated material, must be molsture-conditioned, then be compacted in thin layers using a sheepsfoot roller to achieve 85 to 90 percent compaction. If these soils are treated with kiln dust or cement to aid with moisture conditioning and to add compressive strength, they can be used as structural fill beneath pavements. These soils should not be used beneath foundations, as compaction results can be variable. Where the treated soils are used for backfill of foundation walls, at least 3 feet of free - draining gravel should be placed against the walls. The on site soils cannot be used for geogrid- reinforced fill walls, regardless of whether or not they are treated with kiln dust or cement. Attached are copies of the footprints of the three buildings (labeled A to C from south to north) On these plans are approximate locations of the test pits and borings that have been conducted, and the estimated elevations of dense or hard bearing soils at each location. Where the bearing is noted to be below an elevation, this Is the lowest elevation explored at that location, and suitable bearing soils were not encountered. Augercast concrete piers will likely be needed for the northeastem portion of Building A and the southeastern portion of Building B. The explorations in these areas found deep fill extending at least 10 feet below the planned footing grades. This depth is excessive for overexcavation and structural fill. The extent of the actual extent of the pieced sections can only be determined accurately at the time of building excavation. At least a portion of each of the westem extensions of the buildings, west of the basement floors, will need to be supported on piers, or on deep overexcavated trenches backtllled with lean concrete. Supporting all of these portions of the buildings (slabs and walls) on deeper foundations allows less stringent compaction of backfill below the westem extensions. As summarized below, the basement walls will need to be designed for much higher soil pressures if the westem extensions are not supported on piers or lean concrete- filled trenches. The piers or lean concrete -filled trenches must extend c Sabey Corp. Pape 2 June 9, 1998 JN 98083 below a 1.5 :1 (H:V) zone that slopes up from the base of the lower garage wall to avoid adding a lateral surcharge pressure In addition to the active soil pressure. Design parameters for piers and conventional foundations are presented in our previous report. The high bearing pressure (5,000 psf) can be used for footings that bear on competent soils, or on overexcavations that are backfilled with lean concrete. A lower bearing pressure must be used where footing overexcavations are backfilled with imported granular structural fill (on -site soils, even when treated with kiln dust or cement, are not acceptable for structural fill beneath footings). Three scenarios exist for the design soil pressures behind foundation walls: Scenario 1: The basement walls are constructed as permanent soldier pile walls having a 2,5:1 (H:V) backslope until the permanent concrete walls are constructed. This will be necessary where adequately- sloped cuts cannot be made without encroaching into the steep, westem slopes. As discussed, the benefit of using the shoring walls is that the amount of the excavation behind the basement walls is drastically reduced. This is a significant consideration due to the difficulty of reusing the excavated soils as on -site fill. Active earth pressure - 50 pcf Scenario 2: Foundation walls are backfilled with Imported free- draining granular fill compacted .to 95 percent compaction to support foundations above. Active earth pressure - 40 pcf equivalent active fluid density for cantilever walls, or 55 pcf for restrained walls. Surcharge pressure from westem footing of west extension (if not carried on piers or lean concrete - filled trenches) - 100 psf uniform pressure over entire height of wall. Scenario 3: Foundations walls are backfilled with a minimum 3-foot width of free - draining gravel, then kiln dust - treated on -site soils compacted to at least 90 percent (piers would be used to support foundations on the.backfill zone). Active earth pressure - 50 pcf equivalent active fluid density for cantilever walls, or 60 pcf for restrained walls. Surcharge pressure from westem footing of west extension (If not carried on piers or lean concrete- filled trenches) - 100 psf uniform pressure over entire height of wall. Please call with any questions. oa Nelson- Bourdages - Robert Bouidages (425)828.4850 1 r.ter f/ijul'k. r� ii, t 1' g a) ...i % `;',‘ .4 i 1 a w A, _,,,, ,,,,,, t.., .?. F 0• - Z 09 ' a 9` GEOTECH CONSULTANTS, INC. 13256 NE 20th Street, Suite 16 Bellevue, WA 98005 (425) 747 -5618 FAX 747 -8561 ,- i IVIervlO;..s' "JN ::.8 : JN: 98063 To: Haynes Lund Frame Marc R. McGinnis Company. Sabey Corporation Date: May 18, 1998 Address: 101 Elliott Avenue West, Suite 330 FAX: (206) 281-0920/ Seattle, Washington 98119 -4220 Phone: (206)281 -4200 RE: Additional Considerations for Wall and Foundation Design Pacific View Office Paris Tukwila, Washington R-'.'EIVED Sabc 9 1598 Carpe RECEIVED JUL '1 5 i &3 This memo is an addendum to our March 16, 1998 geotechnical engineering study. The following items are addressed by this addendum: • Reuse of on -site soils as structural fill. • Recommended foundation types for the three buildings following the recently - conducted supplemental test pits. • Design parameters and backfill considerations for the permanent building walls. As we have discussed in our meetings, the on -site soils could be reused as structural fill on a very limited basis. The fine- grained silt soils, which will constitute most of the excavated material, must be moisture - conditioned, then be compacted in thin layers using a sheepsfoot roller to achieve 85 to 90 percent compaction. If these soils are treated with kiln dust or cement to aid with moisture conditioning and to add compressive strength, they can be used as structural fill beneath pavements. These soils should not be used beneath foundations, as compaction results can be variable. Where the treated soils are used for backfill of foundation walls, at least 3 feet of free - draining gravel should be placed against the walls. The on -site soils cannot be used for geogrid- reinforced fill walls, regardless of whether or not they are treated with kiln dust or cement. Attached are copies of the footprints of the three buildings .(labeled A to C from south to north) On these plans are approximate locations of the test pits and borings that have been conducted, and the estimated elevations of dense or hard bearing soils at each location. Where the bearing is noted to be below an elevation, this is the lowest elevation explored at that location, and suitable bearing soils were not encountered. Augercast concrete piers will likely be needed for the northeastern portion of Building A and the southeastern portion of Building B. The explorations in these areas found deep fill extending at least 10 feet below the planned footing grades. This depth is excessive for overexcavation and structural fill. The extent of the actual extent of the piered sections can only be determined accurately at the time of building excavation. At least a portion of each of the western extensions of the buildings, west of the basement floors, will need to be supported on piers. Supporting all of these portions of the buildings (slabs and walls) on piers, prevents the foundations from adding surcharges to the basement walls. As summarized below, the basement walls will need to be designed for much higher soil pressures if piers are not used for the westem extensions. Less stringent compaction of backfill below the westem extensions would also be possible if piers were used, GEOTECH CONSULTANTS, INC. 13256 NE 206 Street, Suite 16 Bellevue, WA 98005 (425) 747 -5618 FAX 747 -8561 r 1 M r , emoi .57/8/".---.1:): JN: 98063 To: Haynes Lund Fin ne Marc R. McGinnis Company. Sabey Corporation. Date: May 18, 1998 Address: 101 Elliott Avenue West, Suite 330 FAX: (206) 281-0920/ Seattle, Washington 98119 -4220 Phone: (206)281 -4200 RE: Additional Consideration for Wall and Foundation Design Pacific View Office Park Tukwila, Washington R" �' IVEQ► i'1 A; 1 9 1998 Sam_ Oorpa RECEIVED JUL S 0 iath3 This memo is an addendum to our March 16, 1998 geotechnical engineering study. The following items are addressed by this addendum: • Reuse of on -site soils as structural fill. • Recommended foundation types for the three buildings following the recently - conducted supplemental test pits. • Design parameters and backfill considerations for the permanent building walls. As we have discussed in our meetings, the on -site soils could be reused as structural fill on a very limited basis. The fine- grained silt soils, which will constitute most of the excavated material, must be moisture - conditioned, then be compacted in thin layers using a sheepsfoot roller to achieve 85 to 90 percent compaction. If these soils are treated with kiln dust or cement to aid with moisture conditioning and to add compressive strength, they can be used as structural fill beneath pavements. These soils should not be used beneath foundations, as compaction results can be variable. Where the treated soils are used for backfill of foundation walls, at least 3 feet of free - draining gravel should be placed against the walls. The on -site soils cannot be used for geogrid- reinforced fill walls, regardless of whether or not they are treated with kiln dust or cement. Attached are copies of, the footprints of the three buildings ,(labeled A to C from south to north) On these plans are approximate locations of the test pits and borings that have been conducted, and the estimated elevations of dense or hard bearing soils at each location. Where the bearing is noted to be below an elevation, this is the lowest elevation explored at that location, and suitable bearing soils were not encountered. Augercast concrete piers will likely be needed for the northeastem portion of Building A and the southeastern portion of Building B. The explorations in these areas found deep fill extending at least 10 feet below the planned footing grades. This depth is excessive for overexcavation and structural fill: • The extent of the actual extent of the piered sections can only be determined accurately at the time of building excavation. At least a portion of each of the western extensions of the buildings, west of the basement floors, will need to be supported on piers. Supporting all of these portions of the buildings (slabs and walls) on piers, prevents the foundations from adding surcharges to the basement walls. As summarized below, the basement walls will need to be designed for much higher soil pressures if piers are not used for the westem extensions. Less stringent compaction of backfill below the westem extensions would also be possible if piers were used. •r Sabey Corp. Page 2 May 18, 1998 JN 98063 Design parameters for piers and conventional foundations are presented in our previous report. The high bearing pressure (5,000 psf) can be used for footings that bear on competent soils, or on overexcavations that are backfilled with lean concrete. A lower bearing pressure must be used where footing overexcavations are backfilled with imported granular structural fill (on -site soils, even when treated with kiln dust or cement, are not acceptable for structural fill beneath footings). Three scenarios exist for the design soil pressures behind foundation walls: Scenario 1: The basement walls are constructed as permanent soldier pile walls having a 2.5 :1 (H:V) backslope until the perrnanent concrete walls are constructed. This will be necessary where adequately- sloped cuts cannot be made without encroaching into the steep, westem slopes. As discussed, the benefit of using the shoring walls is that the amount of the excavation behind the basement walls is drastically reduced. This is a significant consideration due to the difficulty of reusing the excavated soils as on -site fill. Active earth pressure - 50 pcf Scenario 2: Foundation walls are backfilled with imported free - draining granular fill compacted to 95 percent compaction to support foundations above. Active earth pressure - 40 pcf plus a uniform pressure equal to 10 psf multiplied by the wall height to account for restrained walls. Surcharge pressure from westem footing of west extension (if not carried on piers) - 200 psf uniform pressure over entire height of wall. Scenario 3: Foundations walls are backfilled with a minimum 3 -foot width of free - draining gravel, then kiln dust - treated on -site soils compacted to at least 90 percent (piers would be used to support foundations on the backfill zone). Active earth pressure - 50 pcf plus a uniform pressure equal to 10 psf multiplied by the wall height to account for restrained walls. Surcharge pressure from westem footing of west extension (if not carried on piers) - 200 psf uniform pressure over entire height of wall. Please call with any questions. • • t • • • • . • .4 , • 1` GEOTECH CONSULTANTS, INC. 13256 NE 20th Street, Suite 16 Bellevue, WA 98005 (425) 747-5618 FAX (425) 747 -8561 Sabey Corporation 101 Elliott Avenue West, Suite 330 Seattle, Washington 98119 -4220 Attention: Haynes Lund Subject: Preliminary Geotechnical Engineering Study Proposed Pacific View Office Park 12421 Pacific Highway South Tukwila, Washington Dear Mr. Lund: March 16, 1998 JN 98063 We are pleased to present this preliminary geotechnical engineering report for the proposed office complex to be constructed along Pacific Highway South in Tukwila, Washington. The scope of our work consisted of exploring site surface and subsurface conditions, and then developing this report to provide recommendations for general earthwork, and design criteria for foundations and retaining walls. You authorized our work by accepting our confirming proposal dated February 16, 1998. The subsurface conditions of the proposed building site were explored with seven test pits and eight borings that encountered a variable thickness of fill and loose soils overlying glacially - compressed soils. Conventional footings can be used for the buildings where the excavation will be close to the glacially- compressed soils. Augercast piers should be planned in areas of deeper fill and for the western extensions of the buildings over the garage wall backfill. The marginal stability of the steep slopes, and the possibility of future slope movement, must be considered in the site configuration and final grading. The on -site soils,are not acceptable for reuse as structural fill or wall backfill, which will require importing of most fill. The site soils are sensitive to moisture, which will make wet weather grading more costly and difficult. The attached report contains a discussion of the study and our recommendations. Please contact us if there are any questions regarding this report, or if we can be of further assistance during the design and construction phases of this project. MRM: alt Respectfully submitted, GEOTECH CONSULTANTS, INC. Marc R. McGinnis, P.E. Absociate 1 PRELIMINARY GEOTECHNICAL ENGINEERING STUDY Proposed Pacific View Office Park 12421 Pacific Highway South Tukwila, Washington • This report presents the findings and recommendations of our geotechnical engineering study for the site of the proposed office complex in Tukwila. The Vicinity Map, Plate 1, illustrates the general location of the site. We were provided with Sheets CO and SK8 -1 dated February 13 and 10, 1998, respectively. These plans were developed by the Sabey Corporation Architecture Group. The provided plans showed the property dimensions, existing topography on 5 -foot contours, the location of existing structures, and the location and finish floor elevations for the proposed buildings. We anticipate that the site will be developed with four office buildings, each of which will have three floors of tenant space. Beneath the middle two buildings (Buildings B and C) will be a daylight basement parking garage. The northern building (Building D) is to have a daylight basement garage and one more floor of parking beneath the three floors of office space. Paved, on -grade parking will cover most of the remainder of the property. No parking is indicated west of the southern building (Building A), where the building will be cut into the toe of a steep slope. No final grades for the parking areas were available at the time of this report. However, cuts into the toe of the western slope appear likely for construction of the parking west of proposed Buildings B, C, and D. We understand that the configuration of the buildings and pavement areas, as well as final site grading, are still being evaluated, with possible modification from what was indicated on the plans that were provided. SITE CONDITIONS Surface The site is a long, relatively- narrow property that abuts the western edge of Pacific Highway South. At the time of this study, the property was developed with several structures and was being used by Valley Truck and Equipment. This business has an address of 12421 Pacific Highway South. Two of the existing buildings are metal structures located west of proposed Building B, and inside the footprint of proposed Building A. A one -story woodfrarhe office for the business is situated immediately east of the southern metal building. On the northeastern portion of the site is a small sanitary sewer lift station, with several manholes around it. This lift station is operated by the ValVue Sewer District. While not indicated on the provided plans, we understand from discussion with sewer district personnel that the inlet pipe for this lift station crosses onto the site from Pacific Highway South over 100 feet south of the lift station. The outlet pipe generally follows the north property line, extending up the slope toward the west. We understand that all, or a portion, of the sewer system located on the property will be moved or reconfigured in the near future, but possibly not before starting the proposed office complex. It is our understanding that a gas station may once have existed on the site along Pacific Highway South, in the southern portion of the property east of proposed Building B. The property has obviously undergone significant regrading in the past. The ground surface nanaraily Glnnac frown fnwarrl that nnrthataef fn Dnrifir {- linh,A,av Thraa hon•hoc hatiaa hrsPn Sabey Corporation March 16, 1998 JN 98063 Page 2 constructed on the northern approximately two - thirds of the property. These benched areas provide access and parking for trucks and equipment that are being sold and repaired. Between the lower two benches is a short slope having a height of 5 to 10 feet. Between the upper two benches is a taller slope having a height of 25 to 30 feet and an inclination of 60 to 70 percent. These slopes appear to have been constructed by filling. West of the upper bench, the ground slopes steeply up to the adjacent western property, which is developed with an apartment complex. This slope is covered with small- to moderate -sized deciduous trees. Several shallow ditches have been cut across this slope 10 carry surface water, in addition to seepage that exits the slope. In the ditch that crosses the southwestern corner of the site, we observed loose, silty sand and fractured silt overlying glacial till and glacially - compressed silt. The ground surface on the southeastern portion of the site, where the existing office is located, slopes gently down to the edge of Pacific Highway South. This area is covered with asphalt and provides access to the property. The site grade rises above Pacific Highway South over the northern approximately one -half of the property. Near the sewer lift station at the northeast property corner, the slope down to Pacific Highway South from the eastern property line is approximately 15 to 20 feet tall and has an inclination of 50 to 60 percent. History of Slope Instability on Site In 1988, a large landslide affected the northern end of the site, extending upslope onto the adjacent western apartment property. We have been provided with a copy of documents prepared previously by Associated Earth Sciences (AES) and GeoEngineers related to the investigation and repair of this landslide. Based on this information, it appears that a large slump occurred on the steep slope northwest of proposed Building D. The headscarp of this landslide was located approximately 70 feet west of the western property line. Test borings conducted by AES in the slide mass found up to 20 feet of slide debris overlying glacially - compressed silt. An inclinometer installed in the upper portion of the slide found that the slope movement extended to a depth of 15 feet. Two borings (EB -4 and EB -5) were drilled at the base of the slide mass, on the northern end of the upper bench of the site. Stabilization of this landslide consisted of constructing a large concrete rubble buttress at the toe of the slide, with unclassified fill being placed upslope of the buttress to create a final slope of approximately 40 percent. The buttress and this regraded area are still visible. As a part of this slope stabilization, the slope between the upper and middle benches had to be regraded, with a smaller buttress constructed at the toe of this regraded slope in the northern end of proposed Building D. During the course of our site visits, we have observed indications of previous smaller landslides and slope movement elsewhere on the site. The topography on the western slopes above the upper bench is hummocky, and some older tension cracks and scarps were observed. In the vicinity of proposed Building A, there are several small slides at the toe of the slope that have been buttressed with rock fills. In the northern end of the site is a shallow ravine. Downslope of this ravine is a mound of soil that has either resulted from past slope movement or from erosion of soil in the ravine. Subsurface The subsurface conditions were explored by excavating seven test pits and drilling eight borings at Y11__ r11_•_ n TL_ L!_Ir ....1.- ..li.... Sabey Corporation March 16, 1998 JN 98063 Page 3 program was based upon the proposed construction and required . design criteria, the site topography and access, the subsurface conditions revealed during excavation and drilling, the scope of work outlined in our proposal, and on time and budget constraints. The test pits were excavated on February 18, 1998 with a tracked excavator. A geotechnical engineer from our staff observed the excavation process, logged the test pits, and obtained representative samples of the soil encountered. "Grab" samples of selected subsurface soil were collected from the backhoe bucket. The Test Pit Logs are attached to this report as Plates 3 through 6. The borings were drilled on February 16 and 17, 1998, using a truck - mounted, hollow -stem auger drill. Samples were taken at 5 -foot intervals with a standard penetration sampler. This split -spoon sampler, which has a 2 -inch outside diameter, is driven into the soil with a 140 -pound hammer falling 30 inches. The number of blows required to advance the sampler a given distance is an indication of the soil density or consistency. A geotechnical engineer from our staff observed the drilling process, logged the test borings, and obtained representative samples of the soil encountered. The Test Boring Logs are attached as Plates 7 through 14. Generally, the explorations conducted on the site encountered a varying thickness of loose fill or colluvium overlying dense, glacially- compressed silts. Colluvium is soil that has been deposited by erosion or sloughing from the slopes above. Thorough visual evaluation of the samples of glacially - compressed silts that were retrieved showed no indications of significant fracturing or disturbed zones. Slickensides resulting from either stress relief or small slope movement after the glaciers receded were noted in some of the samples. Several of the explorations (8-1, B -2, and B -5) found remnants of glacial till, a glacially - compressed mixture of gravel, silt, and sand, overlying the dense silts. Boring 3, which was drilled on the eastern side of proposed Building B, revealed loose to medium -dense fill to the 17 -foot depth of the boring. This fill is apparently the result of backfilling an excavation for removal of underground storage tanks associated with a previous gas station. Test Pits 3, 4, and 5, excavated in the western portions of proposed Buildings C and D, and in the north end of the site, found fill and unsuitable native soils to the maximum depth of 10 to 13.5 feet that could be explored. Explorations conducted near the toe of the western slope, south of Building D, found several feet of loose fill overlying dense silt. Test Pits 4 and 5, and Borings EB -4 and EB -5 conducted by AES, revealed upwards of 10 feet of old landslide debris overlying dense silt. As discussed previously, borings conducted in the landslide mass northwest of proposed Building D encountered upwards of 20 feet of old slide debris over the glacially- compressed silt. Based on the results of the borings, and our. observations of the soil exposures on the southern portion of the site, it appears that the depth of old landslide debris is greatest on the northern approximately one -half of the property. For clarity, the soil conditions encountered in the explorations are summarized as follows for each of the four buildings: Building A: Up to 4 feet of loose fill or colluvium was encountered overlying dense silt or ' glacial till. Building 6: Test Pit 7, excavated near the northwest building corner, found approximately 5 feet of fill overlying dense silt. The boring drilled east of the building found fill to a depth of 17 feet without encountering competent, native soils. • •. . 1 Sabey Corporation March 16, 1998 J1198063 Page 4 Buildings C and D: The borings conducted in, and near, the eastern portions of these buildings encountered dense silt or glacial till within 5 feet of the existing ground surface. The test pits excavated on the west sides of the buildings were not able to extend through the fill that was encountered to a depth of 10 to 13.5 feet. The final Togs represent our interpretations of the field logs and laboratory tests. The stratification lines on the logs represent the approximate boundaries between soil types at the exploration locations. The actual transition between soil types may be gradual, and subsurface conditions can vary between exploration locations. The logs provide specific subsurface information only at the locations tested. If a transition in soil type occurred between samples in the borings, the depth of the transition was interpreted. The relative densities and moisture descriptions indicated on the test pit or boring logs are interpretive descriptions based on the conditions observed during excavation and drilling. The compaction of backfill was not in the scope of our services. Loose soil will therefore be found in the area of the test pits. If this presents a problem, the backfill will need to be removed and replaced with structural fill during construction. Groundwater Groundwater seepage was observed in Boring 3, and in Test Pits 1 and 7. The depth of seepage ,in these explorations varied between 2.5 and 5 feet. The seepage encountered in Boring 3 appears to be groundwater that has filled the previous tank excavation, with the soils being wet over the entire depth of the exploration. Seepage in Test Pits 1 and 7 appears to be the result of groundwater that is perched above the glacially- compressed silt, which is relatively impermeable. The explorations were left open for only a short time period. Therefore, the lack of seepage observed in the remaining borings and test pits, does not necessarily indicate that no groundwater is present. It is common to encounter groundwater perched above the silt and glacial till, and in sandier zones within these soils, particularly following extended periods of heavy rainfall. CONCLUSIONS AND RECOMMENDATIONS General Based on our observations, and the results of the explorations, the proposed development appears feasible from a geotechnical engineering standpoint. Because the final site configuration and grading are still not finalized, the conclusions and recommendations of this report should be considered preliminary. Conventional foundations bearing on the glacial till or dense silt can be used to support a majority of proposed Buildings A, C, and D. Overexcavation will likely be necessary to expose competent soils in portions of these buildings. If these overexcavations are backfilled with lean concrete, instead of structural fill, the higher allowable bearing pressure recommended below can be used for the foundation design. Due to the depth of unsuitable fill encountered by Boring 3 in proposed Building B, it does not appear that overexcavation to expose competent soils will be feasible for this structure. Therefore, we recommend that deep foundations be planned for this building. However, Sabey Corporation March 16, 1998 JN 98063 Page 5 construction, it is possible that portions of the foundation could be constructed using conventional footings. Augercast concrete piers appear to be one of the most feasible deep foundation systems for use on this building, considering the potential that caving soil and seepage will be encountered in the drilled holes. The western portions of the four buildings will extend over the backfill placed behind the western walls of the below -grade floors. Footings should not be supported on this backfill, as a large surcharge would be exerted on the backfilled walls. For this reason, we suggest that deep foundations consisting of augercast piers be used to support the western extensions of the buildings. The foundation design for all of the buildings should include options for both conventional footings and piers, in order to compensate for varying soil conditions without requiring a redesign of the foundations. Slab -on -grade floors are possible over the existing loose fill or native soils, but some noticeable slab settlement relative to the foundations must be expected. Cracking of the slabs due to settlement can be reduced, but not eliminated, by reinforcing them with a grid of steel bars and by placing at least 12 inches of imported structural fill beneath the slabs. Typically, a grid of No. 4 rebar on 12- to 18 -inch centers is adequate reinforcement. The structural fill should be a well - graded, gravelly fill, such as crushed rock or pit -run sand and gravel. Backfill behind the western basement wall must be well - compacted to limit settlement of the slab floor in the western extensions of the buildings. The steep slopes west of the proposed development have experienced landslides in the past, and will likely be affected by soil movement again in the future. This will occur regardless whether or not the site is developed as planned. Future slope movement on the southern portion of the site appears most likely to occur as mudflows, as the loose, near - surface soils are observed to be relatively thin overlying the glacial till and dense silt. The western slopes are underlain by a significant thickness of old landslide debris on the northern portion of the site. Based on this, and the landslide that occurred in 1988, it appears that deeper slope movement is possible on this portion of the site. The height and inclination of the western slopes makes stabilization impractical. Therefore, the development should be configured in such a way as to minimize the potential for damage to at least the buildings from slope movement. The northern three buildings appear to be adequately set back (over 30 feet) from the toe of the steep slopes to protect them from serious damage from landslides. If proposed Building A cannot be moved at least this far from the toe of the steep slopes, it will be necessary to construct a catchment wall between the building and the slope. The purpose of this catchment wall would be to slow and divert a mudflow traveling down the steep slope. The size and design of this wall would depend on the proximity of the building to the steep slope, but possibly could be incorporated into the western building wall itself. We can provide recommendations for this wall when the final site configuration is determined. The near - surface soils on the western slope are likely standing near their angle of repose. Cutting them at a steeper inclination will likely not be successful for permanent slopes. If it is necessary to grade them steeper, the potential for slope movement and future repair, such as the buttress that was constructed in 1988, will be increased. Cuts at the toe of the steep slopes should be retained by engineered structures that are designed to resist shallow movement on the south portion of the site, and deeper movement on the northern portion. These retaining structures should be founded on the glacially- compressed soils to function properly. Design of retaining structures for these cuts will depend on the final configuration and grading in the parking areas. We understand that rockeries are proposed for these cuts. Generally, rockeries are not intended to retain loose soils, and it is likely that episodes of slope movement would carry away major portions of rockeries over time. Regardless of the type of retaining structure utilized, soil movement upslope is to be Sabey Corporation March 16, 1998 JN 98063 Page 6 anticipated, requiring periodic maintenance, regrading, and revegetation of the slopes. The majority of the steep slope lies on the upslope apartment complex's property, so slope maintenance would likely be conducted in cooperation with the adjacent western property owner. The parking area east of proposed Buildings C and D will extend close to the crest of the steep slope that drops to Pacific Highway South. Soil movement on this slope is possible in the future, but the slope appears to lie entirely on Washington Department of Transportation (WSDOT) property. This would indicate that maintenance of the slope, and repair of landslides, would likely be mainly their responsibility. However, the proposed project must not increase the potential for movement on this slope. Paving the area above the slope, and directing collected surface water to a storm sewer, will have some positive effects on the stability of this slope. No fill or debris should be placed on, or above this slope. The parking lot grading must account for this. Disturbance of the steep slope, and the existing vegetation, must be avoided. Catchbasins and storm sewer pipes, and other utilities, should be moved as far from the crest of this northeastern slope as possible. This reduces the potential for leaks and damage in the event of slope movement. The recommendations of this report are not intended to protect the proposed structures from damage due to falling trees. Attempting to incorporate mitigation for this hazard into the buildings would be very difficult. Wherever possible, sickly or undermined trees should be cut down, and their roots left in place, to reduce the hazard. Water from the existing ditches that extend down the western slope will need to be collected and directed to an appropriate stormwater outfall. This water is originating from groundwater, and from surface runoff from the upslope property. A swale with Catchbasins incorporated into it should be constructed upslope of the retaining structures that will be constructed below the western toe. This will collect other surface runoff not intercepted by the existing ditches. Proper drainage will be important behind the below -grade building walls to reduce the potential for future seepage. Free - draining, imported granular fill should be used as backfill. The silty, on -site soils are not acceptable for use as wall backfill. Performance of all subsurface drainage systems will degrade over time. Therefore, as a minimum, waterproofing should be used for below -grade areas that will be occupied, or for areas that will serve as mechanical, electrical, or storage spaces. The silt encountered in our explorations was originally deposited as lake sediment before being glacially consolidated. These deposits usually contain bedding planes that are often not horizontal. Bedding that dips down into an excavation can sometimes cause localized soil failures in the excavation face. Flatter, temporarily cut slopes, shoring, or buttressing of cut slopes may be necessary, depending on the bedding encountered during excavation. Our personnel can assist with remedial procedures, if the bedding becomes a significant consideration during excavation. The on -site soils will not be suitable for reuse as structural fill or wall backfill due to their high silt and moisture contents. Imported granular fill should be planned, including for utility trench backfill in pavement or slab areas. Grading and earthwork on this site will certainly be more costly and difficult during wet weather, as the on -site soils are highly sensitive to moisture. Excavated footing subgrades should be protected with a thin (3 to 4 inches) layer of crushed rock or lean concrete to protect them from disturbance during placement of forms and reinforcement for the foundations. All disturbed and softened soils would need to be removed prior to pouring concrete, which can be a difficult process once the reinforcing steel is in place. Sabey Corporation March 16, 1998 J N . 98063 Page 7 The silty subgrade soils will soften easily under pavements unless gravelly imported fill is placed beneath pavement sections. Generally, 9 inches of structural fill should be planned beneath pavement sections in parking and Tight traffic areas. At least 12 inches of imported structural fill should be used in heavy traffic areas, such as main entrances and drivelanes, and around dumpsters and other possible areas of truck traffic. Geotech Consultants, Inc. should be involved in the design of site retaining structures once the sit grading has been finalized. We should also be allowed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work for this study, and it may include revisions to our recommendations to accommodate site, development, and geotechnical constraints that become more evident during the review process. Conventional Foundations Conventional footings to support the proposed buildings must bear on undisturbed, glacial till or dense silt, or on imported, granular structural fill placed above these competent, native soils. Footings bearing on structural fill will need to be designed for a lower allowable bearing pressure. See the later sub - section entitled General Earthwork and Structural Fill for recommendations regarding the placement and compaction of structural fill beneath structures. We recommend that continuous and individual spread footings have minimum widths of 16 and 24 inches, respectively. They should be bottomed at least 12 inches below the lowest adjacent finish ground surface for frost protection. The local building codes should be reviewed to determine if different footing widths or embedment depths are required. Footing subgrades must be cleaned of loose or disturbed soil prior to pouring concrete. Depending upon site and equipment constraints, this may require removing the disturbed soil by hand. Overexcavation will likely be required below portions of the foundations in each building to expose competent, native soil. Unless lean concrete is used to fill an overexcavated hole, the overexcavation must be at least as wide at the bottom as the sum of the depth of the overexcavation and the footing width. For example, an overexcavation extending 2 feet below the bottom of a 3 -foot -wide footing must be at least 5 feet wide at the base of the excavation. If lean concrete is used, the overexcavation need only extend 6 inches beyond the edges of the footing. The following allowable bearing pressures are appropriate for footings constructed according to the above recommendations: Bearing Condition Allowable Bearing Pressure Bearing directly, or on lean concrete, above competent native soil 5,000 psf Supported on structural fill placed above competent native soil 1 3,000 psf Where: (1) psf is pounds per square foot. • Sabey Corporation March 16, 1998 JN 98063 Page 8 A one -third increase in the above design bearing pressures may be used when considering short - term wind or seismic Toads. For the above design criteria, it is anticipated that the total post - construction settlement of footings founded on competent, native soil, or on structural fill up to 5 feet in thickness, will be less than two - thirds of an inch, with differential settlements on the order of one -half inch in a distance of 50 feet along a continuous footing. Larger differential settlements could occur where more than 5 feet of structural fill is used beneath foundations. Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the bearing soil, or by passive earth pressure acting on the vertical, embedded portions of the foundation. For the latter condition, the foundation must be either poured directly against relatively level, undisturbed soil or surrounded by level, structural fill. We recommend using the following design values for the foundation's resistance to lateral loading: Parameter Design Value Coefficient of Friction Passive Earth Pressure 0.40 300 pcf Where: (i) pcf Is pounds per cubic foot, and (I1) passive earth pressure Is computed using the equivalent fluid density. • If the ground in front of a foundation is loose or sloping, the passive earth pressure given above will not be appropriate. We recommend a safety factor of at least 1.5 for the foundation's resistance to lateral loading, when using the above design values. Auqercast Concrete Piers Drilled piers should be used to support the buildings in areas of deep fill, such as beneath proposed Building B, or where the western sides of the building will extend over backfill for the parking garage walls. These piers should be constructed using augercast methods, which allows pier installation where caving soils or groundwater are present. Augercast piers are installed using continuous flight, hollow -stem auger equipment. Concrete grout must be pumped continuously through the auger as it is withdrawn. We recommend that augercast piers be installed by an experienced contractor who is familiar with the anticipated subsurface conditions. An allowable compressive capacity of 40 tons can be attained by installing a 16- inch - diameter, augercast concrete pier at least 10 feet into dense, native soil. For 15 feet of embedment, an allowable capacity of 50 tons is appropriate. For transient loading, such as wind or seismic loads, the allowable pier capacity may be increased by one - third. We can provide design criteria for different pier diameters and embedment lengths, if greater capacities are required. The minimum center -to- center pier spacing should be three times the pier diameter, We estimate that the total settlement of single piers installed as described above will be on the order of one -half inch, Most of this settlement should occur during the construction phase as the dead loads are applied.. The remaining post- construction settlement would be realized as the live - loads are applied. We estimate that differential settlements over any portion of the structures Sabey Corporation March 16, 1998 ' JN 98063 Page 9 We recommend reinforcing each pier its entire length. This typically consists of a rebar cage extending a portion of the pier's length with a full - length center bar. Each pier can be assumed to have a point of fixity at 10 feet below the ground surface for the computation of lateral load resistance. The loose soil against the piers can be assumed to have a design passive earth resistance of 150 pounds per cubic foot (pcf) acting on two times the pier diameter. Passive earth pressures on the grade beams will also provide some lateral resistance. If structural fill is placed against the outside of the grade beams, the design passive earth pressure from the fill can be assumed to be equal to that pressure exerted by an equivalent fluid with a density of 200 pcf. Seismic Considerations The site is located within Seismic Zone 3, as illustrated on Figure No. 16 -2 of the 1994 Uniform Building Code (UBC). In accordance with Table 16 -J of the 1994 UBC, the site soil profile is best represented by Profile Type S2. The glacially - compressed silts and silty sands that will support the foundations are not susceptible to seismic liquefaction. Slabs -on -Grade All slabs -on -grade should be underlain by a capillary break or drainage layer consisting of a minimum 4 -inch thickness of coarse, free - draining, structural fill with a gradation similar to that . discussed later in Permanent Foundation and Retaining Walls. In areas where the passage of moisture through the slab is undesirable, a vapor barrier, such as a 6 -mil plastic membrane, should be placed beneath the slab. Additionally, sand should be used in the fine- grading process to reduce damage to the vapor barrier, to provide uniform support under the slab, and to reduce shrinkage cracking by improving the concrete curing process. We recommend placing concrete slabs over at least 1 foot of structural fill to provide more uniform support for the slab where the subgrade is soft or settles more rapidly than the surrounding ground. Isolation joints should be provided where the slabs intersect columns and walls. As discussed above in the General section, rebar should also be used in the slabs to reduce cracking from differential slab settlement. Control and expansion joints should also be used to control cracking from expansion and contraction. Saw cuts or preformed strip joints used to control shrinkage cracking should extend through the upper one - fourth of the slab. The spacing of control or expansion joints depends on the slab shape and the amount of steel placed in it. Permanent Foundation and Retaining Walls Retaining walls backfilled on only one side should be designed to resist the lateral earth pressures imposed by the soil they retain. The following recommended design parameters are for walls that restrain level backfill: Sabey Corporation March 16, 1998 Parameter Design Value Active Earth Pressure • 40 pcf Passive Earth Pressure 300 pcf Coefficient of Friction 0.40 Soil Unit Weight 130 pcf Where: (i) pcf Is pounds per cubic foot, and (ii) active and passive earth pressures are computed using the equivalent fluid pressures. • For a restrained wall that cannot deflect at least 0.002 times Its height, a uniform lateral pressure equal to 10 psf times the height of the wall should be added to the above active equivalent fluid pressure. JN.98063 Page 10 The values given above are to be used to design permanent foundation and retaining walls only. The passive pressure given is appropriate for the depth of level, structural fill placed in front of a retaining or foundation wall only. We recommend a safety factor of at least 1.5 for overturning and sliding, when using the above values to design the walls. The design values given above do not include the effects of any hydrostatic pressures behind the walls and assume that no surcharge slopes or Toads, such as vehicles, will be placed behind the walls. If these conditions exist, those pressures should be added to the above lateral soil pressures. Also, if sloping backfill is desired behind the walls, we will need to be given the wall dimensions and the slope of the backfill in order to provide the appropriate design earth pressures. The surcharge due to traffic loads behind a wall can typically be accounted for by adding a uniform pressure equal to 2 feet multiplied by the above active fluid density. Heavy construction equipment should not be operated behind retaining and foundation walls within a distance equal to the height of a wall, unless the walls are designed for the additional lateral pressures resulting from the equipment. The wall design criteria assume that the backfill will be well - compacted in lifts no thicker than 12 inches. The compaction of backfill near the walls should be accomplished with hand - operated equipment to prevent the walls from being overloaded by the higher soil forces that occur during compaction. Retaining Wall Backfill Backfill placed behind retaining or foundation• walls should be coarse, free- draining, structural fill containing no organics. This backfill should contain no more than 5 percent silt or clay particles and have no gravel greater than 4 inches in diameter. The percentage of particles passing the No, 4 sieve should be between 25 and 70 percent. The silty, on -site soils are not free - draining and should not be used for retaining wall backfill. Additionally, due to their low compacted strengths, the on -site soils would exert a much higher lateral Toad on the walls than is recommended above The purpose of these backfill requirements is to ensure that the design criteria for a retaining wall are not exceeded because of a build -up of hydrostatic pressure behind the Sabey Corporation March 16, 1998 JN 98063 Page 11 wall. The top 12 to 18 inches of the backfill should consist of a compacted, relatively impermeable soil or topsoil, or the surface should be paved. The ground surface must also slope away from backfiiled walls to reduce the potential for surface water to percolate into the backfill. The sub- section entitled General Earthwork and Structural Fill contains recommendations regarding the placement and compaction of structural fill behind retaining and foundation walls. The above recommendations are not intended to waterproof the below -grade wails. If some seepage through the walls or moist conditions are not acceptable, damp - proofing or waterproofing should be provided. This could include limiting cold joints and wall penetrations, and possibly using bentonite panels or membranes on the outside of the walls. Applying a thin coat of asphalt emulsion is not considered waterproofing, but it will only help to prevent moisture, generated from water vapor or capillary action, from seeping through the concrete. Excavations and Slopes Excavation slopes should not exceed the limits specified in local, state, and national government safety regulations. Based upon Washington Administrative Code (WAC) 296, Part N, the soil type at the subject site would generally be classified as Type C. Therefore, temporary cut slopes should not be excavated at an inclination steeper than 1.5:1 (Horizontal:Vertical), extending continuously between the top and the bottom of a cut. Due to the loose, occasionally wet condition of the near - surface soils, and the likely presence of inclined bedding or fracture planes in the glacially - compressed silts, it is likely that additional measures may be necessary to provide stable temporary cut slopes in some areas. These measures could consist of flatter cut slopes, shoring, or constructing rock buttresses. The above recommended temporary slope recommendations are based on what has been successful at other sites with similar soil conditions. Temporary cuts are those that will remain unsupported for a relatively short duration to allow for the construction of foundations, retaining walls, or utilities. Temporary cut slopes should be protected with plastic sheeting during wet weather. The cut slopes should also be backfiiled or retained as soon as possible to reduce the potential for instability. All permanent cuts into the near - surface, loose native soil should be inclined no steeper than 2.5:1 (H:V). In areas of excessively poor soil, it may be necessary to use flatter permanent slopes, or to reconstruct and buttress the cut slope using quarry spalls or a similar fill material. Fill slopes constructed of imported granular fill should not be constructed with an inclination greater than 2:1 (H:V). To reduce the potential for shallow sloughing, fill must be compacted to the face of these slopes. This could be accomplished by overbuilding the compacted fill and then trimming it back to its final inclination. Water should not be allowed to flow uncontrolled over the top of any temporary or permanent slope. Also, all permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve the stability of the surficial layer of soil. Sabey Corporation March 16, 1998 Drainage Considerations JN 98063 Page 12 We recommend the use of footing drains at the base of all perimeter footings and at the base of all backfilled, earth- retaining walls. These drains should be surrounded by at least 6 inches of 1 -inch- minus, washed rock and then wrapped in non - woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar material). At its highest point, a perforated pipe invert should be at least as low as the bottom of the footing, and it should be sloped for drainage. Drainage should also be provided inside the footprint of a .structure, where (1) a crawl space will slope or be lower than the surrounding ground surface, (2) an excavation encounters significant seepage, or (3) an excavation for a building will be close to the expected high groundwater elevations. We can provide recommendations for interior drains, should they become necessary, during excavation and foundation construction. All roof and surface water drains must be kept separate from the foundation drain system. A typical drain detail is attached to this report as Plate 15. For the best long -term performance, perforated PVC pipe is recommended for all subsurface drains, Groundwater was observed during our field work. If seepage is encountered in an excavation, it should be drained from the site by directing it through drainage ditches, perforated pipe, or French drains, or by pumping it from sumps interconnected by shallow connector trenches at the bottom of the excavation. The excavation and site should be graded so that surface water is directed off the site and away from the tops of slopes. Water should not be allowed to stand in any area where foundations, slabs, or pavements are to be constructed. Final site grading in areas adjacent to buildings should slope away at least 2 percent, except where the area is paved. Water from roof, storm water, and foundation drains should not be discharged onto slopes; it should be tightlined to a suitable outfall located away from any slopes. General Earthwork and Structural Fill All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. The stripped or removed materials should not be mixed with any materials to be used as structural fill, but they could be used in non - structural areas, such as landscape beds. Structural fill is defined as any fill placed under a building, behind permanent retaining or foundation walls, or in other areas where the underlying soil needs to support Toads. All structural fill should be placed in horizontal lifts with a moisture content at, or near, the optimum moisture content. The optimum moisture content is that moisture content that results in the greatest compacted dry density. The moisture content of fill is very important and must be closely controlled during the filling and compaction process. The allowable thickness of the fill lift will depend on the material type selected, the compaction equipment used, and the number of passes made to compact the lift. The loose lift thickness should not exceed 12 inches, We recommend testing the fill as it is placed. If the fill is not compacted to specifications, it can be recompacted before another lift is placed. This eliminates Sabey Corporation March 16, 1998 JN 98063 Page 13 the need to remove the fill to achieve the required compaction. The following table presents recommended relative compactions for structural fill: Location of Fill Placement Minimum Relative Compaction Beneath footings, slabs i 95% or walkways Behind retaining walls 90% Beneath pavements 95% for upper 12 inches of subgrade; 90% below that level Where: Minimum Relative Compaction Is the ratio, expressed In percentages, of the compacted dry density to the maximum dry density, as determined in accordance with ASTM Test Designation D 1557.78 (Modified Proctor). The on -site soils are not suitable for reuse as structural fill due to their high silt and moisture contents. Structural fill that will be placed in wet weather should consist of a coarse, granular soil with a silt or clay content of no more than 5 percent. The percentage of particles passing the No, 200 sieve should be measured from that portion of soil passing the three - quarter -inch sieve. LIMITATIONS The conclusions and recommendations contained in this report are based on site conditions as they existed at the time of our exploration and assume that the soil encountered in the test pits and borings is representative of subsurface conditions on the site. If the subsurface conditions encountered during construction are significantly different from those observed in our explorations, we should be advised at once so that we can review these conditions and reconsider our recommendations where necessary. Unanticipated soil conditions are commonly encountered on construction sites and cannot be fully anticipated by merely taking soil samples in test pits and borings. Subsurface conditions can also vary between exploration locations, Such unexpected conditions frequently require making additional expenditures to attain a properly constructed project. It is recommended that the owner consider providing a contingency fund to accommodate such potential extra costs and risks. This is a standard recommendation for all projects. The recommendations presented in this report are directed toward the protection of only the proposed structures from damage due to slope movement. Predicting the effects of development on the stability of slopes is an inexact and imperfect science that is currently based mostly on the past behavior of slopes with similar characteristics. ' Landslides and soil movement can occur on steep slopes before, during, or after the development of property. The owner must ultimately accept the possibility that slope movement could occur, resulting in possible Toss of ground or damage to the facilities around the proposed building. This report has been prepared for the exclusive use of Sabey Corporation, and its representatives, for specific application to this project and site, Our recommendations and conclusions are based on observed site materials, and selective laboratory testing and engineering analyses. Our conclusions and recommendations are professional opinions derived in accordance with current standards of practice within the scope of our services and within budget and time constraints. No Sabey Corporation March 16, 1998 JN' 98063 Page 14 warranty is expressed or implied. The scope of our services does not* include services related to construction safety precautions, and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. We recommend including this report, in its entirety, in the project contract documents so the contractor may be aware of our findings. ADDITIONAL SERVICES Geotech Consultants, Inc. should be retained to provide geotechnical consultation, testing, and observation services during construction. This is to confirm that subsurface conditions are consistent with those indicated by our exploration, to evaluate whether earthwork and foundation construction activities comply with the general intent of the recommendations presented in this report, and to provide suggestions for design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. However, our work would not include the supervision or direction of the actual work of the contractor and its employees or agents. Also, job and site safety, and dimensional measurements, will be the responsibility of the contractor. The following plates are attached to complete this report: Plate 1 Vicinity Map Plate 2 Site Exploration Plpn Plates 3 - 6 Test Pit Logs Plates 7 - 14 Boring Logs Plate 15 Footing Drain Detail Attachments Previous Boring Logs Sabey Corporation March 16, 1998 JN'98063 Page 15 We appreciate the opportunity to be of service on this project. If you have any questions, or if we may be of further service, please do not hesitate to contact us. MRM /JRF: alt Respectfully submitted, GEOTECH CONSULTANTS, INC. IEXPIRES 1025/7 1 Marc R. McGinnis, P.E. Associate James R. Finley, P.E. Principal i �r // / /! / � -- r • / -- — .plc' ..- / / / / / / / , III/ // / /" j- _� / //O p-r1 �_ -�' / / • / / .- -- 1j1 // ■ / / / / / / .111 IIJ Int / O TP -6 I.0 ' / / C .i / ‘tai / • — _ — / TP -4 / J r - `� - - - / /' B -5 / / • . • ' / TP- �"- 2 • r `'1S B -4 ■•••■ ....••••••• — — •• 'f 1 r / TP -3 O / / f9 B -3 /-J / / / • LEGEND: ■ B -6 - PROPOSED BUILDINGS L J EXISTING BUILDINGS Q APPROXIMATE TEST PI • APPROXIMATE BORING. e APPROXIMATE BORING oPP GEOTECH CONSULTANTS \%.:4 / / -/' / , ' / i / -. 1/ / / / / / -i ''/ ----" �/' B -5 / / �'/ / ��/ - / • // /1 \ —:o /1 ® tor TP-5 / ' ,. ./ � r EB -5/N J -�-- / 1 ,./ !�0 EB-4 -- r,�. %/ /4�/ 1 / / TP -4 . . -- / / - 1- • J / • - --Gil TP -2 • J � � .s B -4 .-- _r -- l r . -- - / / �� J - J - / J O' B -3 �`G�� � pG`F�G PI G IG LEGEND: B -6 ElPROPOSED BUILDINGS r-� L _J EXISTING BUILDINGS 0 APPROXIMATE TEST PIT LOCATIONS FOR CURRENT STUDY S APPROXIMATE BORING LOCATIONS FOR CURRENT STUDY e APPROXIMATE BORING LOCATIONS BY ASSOCIATED EARTH SCIENCES (MAY 1998) GEOTECH CONSULTANTS SITE EXPLORATION PLAN 12421 PACIFIC HIGHWAY SOUTH TUKWILA, WA 40: :sKt.3; 35o sr • 3 91m sr qsr4 Sr SOTH ST 1015r 41 L5 1▪ ;• 11,110 ‘r, 14' EVt\ D c• PI • cr 5 . ARBOR LAXE ,re OAR< S •.: • RBOR LAKE T T ,.., .40 71 -0 1. — *L.ST ,,,, RAINIER .• 1 ;■ '''' 5 GOLF (II N,t. 1.'4 b kik all i$S11 T- 21" .. • .. x •• c.) COUNTRY. 11,51■Iii: I i%. O : ACCESS R ,.... ; '.. 4,--;)4.-1.291rs S. 151,„, Sr SOUTHERN Ntrarir:: frARA• S I 22 40 u1 111 S MTN — IITH ST 130r. 136TH = > • S i4ist I tel ... •• Q 5 14,`,01 ..77 S:t4P.12 S I ST $▪ 9144STTH 1r - la- - -ST"' S r 1 FusrER '1 M.h•i• • 1 r— I VI M., I% GEOTECH CONSULTANTS VICINITY MAP 12421 PACIFIC HIGHWAY SOUTH TUKWILA, WA 10 15 5 • 1 cfr 9 Go ,cop ‘) TEST PIT 1 Description NMI eeei • G Dark brown SAND and SILT, with organics, wet, soft Brown, sandy SILT, very moist, soft to medium -stiff (Colluvlum) . Brown SILT, with some gravel, moist, dense to very dense • Test Plt was terminated at 8 feet on February 18, 1998. • Moderate groundwater seepage was observed at 2.6 feet during excavation. • Caving was observed from top to 2.5 feet during excavation. TEST PIT 2 Description gang FILL 11111 ML 1I11I Crushed concrete with organics (FILL) Brown, slightly sandy SILT, low plasticity, moist, very dense M� j Gray SILT, tow plasticity, moist, very dense • Test Pit was terminated at 5 feet on Fobruary 18, 1998. • No groundwater seepage was observed during excavation. • No caving was observed during excavation. GEOTECH CONSULTANTS, INC. TEST PIT LOG 12421 Pacific Highway South Tukwila, Washington Job No: I Date: 1 Logged by: 98063 February 19981 DBG EPIate: 10 15 5 10 15 TEST PIT 3 Description. NMI MIN INIMMS 1 t� e .4, 9(2,4 v'ciciv FILL Brown SAND and SILT, with organics (FILL) Brown SILT, very moist to wet, soft (FILL) FILL FILL Dark gray, sandy SILT, with some gravel and organics, soft to medium-stiff (FILL or Colluvlum) • Test Plt was terminated at 10 feet on February 18, 1998. " No groundwater seepage was observed during excavation. • Caving was observed during excavation. TEST PIT 4 Description PIM IMO IMMO Yaw OMNI MEM MEMO Brown -gray, sandy SILT with some gravel, very moist, soft (FILL) FILL Dark gray, sandy SILT, with organics and Togs, soft (FILL or Slide Debris) FILL • Test Pit was terminated at 13.5 feet on February 18, 1998. • No groundwater seepage was observed during excavation. • Minor caving was observed during excavation. GEOTECH CONSULTANTS, LW. TEST PIT LOG 12421 Pacific Highway South Tukwila, Washington (Job No: 98063 Date: February 19981 Logged by: T Plate: DBG 10 e.,40,e6 e +01/4 C t TEST PIT 5 Description MON MEI 15-- 5 10 15 FILL Concrete rubble, with brown, sandy SILT (FILL) ML Brown -gray, sandy SILT, with organics, moist to very moist, medium -stiff (Slide Debris) - 6 foot diameter log encountered OL PT Dark brown, organic SILT to PEAT �4 �o<s): 1GS • Test Pit was terminated at 12 feet on February 18, 1998. • No groundwater seepage was observed during excavation. • No caving was observed during excavation. TEST PIT 6 Description r OMR r• Crushed rock and cobbles, with brown, silty SAND (FILL) FILL Dark brown to gray, silty SAND, with some gravel, wet, medium -dense (FILL) FILL - hydrocarbon odor L. 1 I Brown SILT, low plasticity, moist, very dense • Test Pit was terminated at 7.5 feet on February 18, 1998. • No groundwater seepage was observed during excavation. • No caving was observed during excavation. GEOTECH CONSULTANTS, INC. TEST PIT LOG 12421 Pacific Highway South Tukwila, Washington Job No: I Date: Logged by: illate: 98063 February 1998 DBr3 5 TEST PIT 7 Description. Brown SAND and SILT, with wood debris, moist, medium -dense (FILL) FILL Brown SILT, low plasticity, moist, very dense • Test Pit was terminated at 7 feet on February 18, 1998. • Minor groundwater seepage was observed at 5 feet during excavation. • No caving was observed during excavation. 10 15 GEOTECH CONSULTANTS, INC. TEST PIT LOG 12421 Pacific Highway South Tukwila, Washington Job No: Date: Logged by: Pater 98063 1 February 19981 DBt3, e I., 5 10 15 20 25 30 35 40 70 75/6" 65/6" 95 75/11" ti cp N i I1 11 11 II 11 II II 11 11 11 SM • ,1 BORING 1 Description . Brown, gravelly, silty SAND, moist, very dense (Glacial Till) Gray SILT, low plasticity, massive, moist, very dense ML • Boring was drilled to 26 feet on February 16, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. 1 BORING LOG 12421 Pacific Highway South Tukwila, Washington IJob No: I Date: I Logged b !Mate: 98063 February 1998 DBO 7 10 15 20 25 30 35 • �< o-�o �oto e 40 co5 `�se 5 �5 BORING 2 Description . N EM IMMON IOW ImM M. PON 40-- 23.0% 80/11" 78 80 82 75/6" 0 it I II II 1111 IIII 1111 1111 11 [SM Gray, gravelly, silty SAND, moist, very dense (Glacial Till) M Tan to gray, clayey SILT, with occasional slickensides, moist, hard LL= 37.1, P1 =1 4.1 - becomes sandy, non - plastic, very dense • Boring was drilled to 30.5 feet on February 16, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. BORING LOG 12421 Pacific Highway South Tukwila, Washington 'Job No: I Date: I Logged by: 98063 February 1998 DB Plate: 8 J 1 BORING 3 Description, MIS 10 MOW 15 20 25 30 35 40 9 18 59 FILL Dark brown to gray, gravelly, silty SAND, with some wood debris, wet, loose to medium -dense (FILL) - hydrocarbon odor - becomes very gravelly • Boring was drilled to 17 feet on February 16, 1998. • Water level measured In monitoring well on February 18, 1998 at 4.5 feet. BORING LOG 12421 Pacific Highway South Tukwila, Washington Job No: 98063 Date: Loomed r February 1998 �B Pirate: 10 15 20 25 30 35 BORING 4 CP co Description • W Mmomml Wee IMO 40-- 24.0% 85/10" 80 74 80 50/6" 50/4" 5 ❑ ;I Brown, silty SAND, fine-grained, moist, medium -dense SM '1 11/11111/ iI ML Brown SILT, fow plasticity, massive, moist, very dense - becomes gray LL =38.8,P1 =14.8 - becomes wet ML 11 Light brown, sandy SILT, low plasticity, moist, very dense • Boring was drilled to 31 feet on February 17, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. BORING LOG 12421 Pacific Highway South Tukwila, Washington Job No: � Date: Logged �: 98063 February 1998 D9 Plate: 10 • • 1 u , • r 10 15 20 25 30 35 o� cp � .� Co „k0 tio� t4O \� BORING 5 Description• IMM MOO MOM OEM 40-- 23.5% 23.3% 86 50/6" 78 71 75 2 Ei Brown to gray, silty, gravelly SAND, moist, loose (FILL) FILL Old Topsoil I ;I ;I ;I ;I; SM ML Gray, silty SAND, with trace of gravel, moist, dense to very dense Brown, sandy SILT, non - plastic, moist, very dense LL 33.8, PI =10.3 Brown, gravelly, silty SAND, fine- grained, moist, very dense (Glacial fill) SM ML Gray SILT, low plasticity, massive, very dense LL=32.1, P1 =8.8 • Boring was drilled to 31 feet on February 17, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. BORING LOG 12421 Pacific Highway South Tukwila, Washington Job No: 98063 Date: Logged by: February 1998 DBG Plate: 11 10 15 20 25 30 35 40 BORING 6 Description Win MeNNO .. • IMO NNW 80 79 80 Brown, gravelly, silty SAND, fine- grained, very moist, loose (FILL) FILL Brown, sandy SILT, non - plastic, moist, very dense ML • Boring was drilled to 18 feet on February 17, 1998. • No groundwater seepage was encountered during drilling. BORING LOG 12421 Pacific Highway South Tukwila, Washington I Job No: I Date: Lo ►wed by 98063 February 1998 I DBO Plate: 12 1 • • , ,, 1 • • , 10 15 20 25 30 35 40 0 BORING 7 Description r ImM r Mine 25.0% 79 87 5016" 78 75 3E0 5 0 Brown, very silty SAND, very moist, loose (FILL) FILL ML Brown, sandy SILT, low plasticity, moist, very dense - becomes gray with occasional gravel ML Gray, clayey SILT, with occasional slIckensides and fractures, medium- plasticity, moist, hard LL=36.4, PI =11.4 ML Gray SILT, low plasticity, moist, very dense • Boring was drilled to 28 feet on February 17, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. 1 BORING LOG, 12421 Pacific Highway South Tukwila, Washington IJob No: I Date: 'Logged b: I Plate: QA063 Fahn1ary 199A DB 13 o ,�19y� N'K ?`4�t cfr \)5 BORING 8 Description MEI 10r- 15 --- 22.5% 20 — 25 30 35 WINO 40— 78 80 74 70 79 El 6 Q Dark brown, gravelly, silty SAND, very moist, medium -dense (FILL) FILL Brown, slightly sandy SILT, tow plasticity, moist, very dense M Gray SILT, low plasticity, massive, moist, very dense LL .37.3, P1 =9.8 ML • Boring was drilled to 31.5 feet'on February 17, 1998. • No groundwater seepage was encountered during drilling. GEOTECH CONSULTANTS, INC. BORING LOG 12421 Pacific Highway South Tukwila, Washington I Job No: 1 Date: 1 Logged by: �' Plate: 1 98063 February 19981 DBO 14 • 1I i r • Slope backfil/ owoy from /oundo /ion. --� WASHED ROCK ��--- T/GHTLINE ROOF DRAIN Do no/ connec/ to fooling drain, SACK-W.1. See /ex/ /or requ /remen /s. 6 min. NONWOVEN GEOTEXT /LE FILTER FABRIC SLAB VAPOR BARRIER „ \ i� sr ♦ ■ �� it % � ; • •l' `< •, 4 min. FREE -DRAINING SAND /GRAVEL 4" PERFORATED HARD PVC PIPE /aver/ of leas/ as /ow as fooling and /or craw/ space. Slope to drain. Ploce . weepho/es downward. GEOTECH < ' CONSULTANTS FOOTING DRAIN DETAIL 12421 PACIFIC HIGHWAY SOUTH TUKWILA, WA, • . • r *, '88 06/20 09141 1HE TECT0:1 Co EXPLORATION BORING LOG EB -4 QRAPH USCS SEDIMENT DESCRIPTION DEPTH 1 u 0 81A?IDAADMMITRAT10M11ltIlITAMtt 10 20 30 40 • Damp, brown and grey, mottled, slightly oxidized,'gravelly, silty, fine to coarse sand with occassional organics, • 5 1 IDry 1 Z .IL 1 1 i I I ♦ II • to damp, brown and grey; mottled, slightly oxidized, silt with occassionel clay and very fine sand. •io 15 20 35 53 Becoming dark grey to light grey silt. • , 1._..�.�, ,•. i paw, 1 ?.h %v 10PA • r , '88 06/20 09142 THE TECTOH Co 12 [ EXPLORATION BORING LOG EB -4 •- Imo ORAPN 5-WC; SEDIMENT DESCRIPTION DEPTH r s < 11 ITAHOAA0 ►1$ITAAT10N PI tSt$TAMCE ' Mo.1n99T 10 20 $0 40 v ' As above • • 45 50 55 60 65 70 75 A • • with thin interbeds of very fine sand and clay i Zi • • 55 ._ T 52 w 60 50/2 Wet, grey, equigranular fine sand with some gravel and thin beds of dark grey and light grey silt, T _________ ......, '88 86/20 09:42 ..r THE TECTOH Co AMOM LORATION BORING LOG BB-4 13 GRAPH I [sosn SEDIMENT DESCRIPTION DEPTH E ; IITA110Al13IlMLTAAMOM 10 20 at „ ,, ,,,, i0 REIM/ACE 40 .___.. .r. .__._._ Wet, grey, fine to coarse sand and gravel. _ • i BOH 84' • --' 85 —' 90 -. — r-- — r' ,1 r.. ,. �r 'e0 06/20 09143 � 'THE THE TECTCH Co ATION BORING LOG Es--5 • 14 GRAPH Sosn SEDIMENT DESCRIPTION DEPTH ITAMOAt1e HMt? *ATOM U$IITAMC! ' wort „„r 10 20 20 40 ' Damp, brown and grey, mottled, slightly oxidized, .gravelly, silty, fine to coarse sand. 5 10 15 1 T ,_j_, 1 J I I ♦ • with manor organics • Damp, brown and grey, slightly oxidized, silt with occassiona].— very f�.ne• ssnd. Becoming grey silt with occassional very fine sand. 20 • 25 30 35 BON 23 1/2' • TECHNICAL INFORMATION REPORT MO/6w for: Pacific View Office Park 12421 Pacific Highway South Tukwila, Washington June 10, 1998 1. Project Overview II. Preliminary Conditions Summary Ill. Off-Site Analysis IV. Retention/Detention Analysis and Design V. Conveyance Systems Analysis and Design VI. Special Reports and Studies VII. Basin and Community Planning Areas VIII. Other Permits IX. Erosion /Sedimentation Control Design X. Bond Quantities Worksheet, Retention/Detention Facility Summary Sheet, Sketch and Declaration of Covenant XI. Maintenance and Operations Manual 010 Nelson - Bourdages a Division of Poggemeyer Design Group, Inc. NB Job No 98020C RECEIVED JUL 1 61998 1 EXPIRES : 11 -11- 91 NELSON- BOURDAGES a Division of Poggemeyer Design Group, Inc. 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827-5995 • Fax (425) 828.4850 RECEIVED CITY OF TUKWILA JUN 151998. PERMIT CENTER Technical Information Report Pacific View Office Park 12421 Pacific Highway South Tukwila, Washington June 6, 1998 SECTION I - PROJECT OVERVIEW The project site is located on the west tributary of the Riverton Creek Drainage Basin at 12421 Pacific Highway South, just south of the SR99 and SR599 intersection. (See Figure 2). The project consists of construction of three buildings to house approximately 51,250 square feet of light manufacturing space (Classification F -2) and approximately 173,250 square feet of office space (Classification B). The project includes parking at a ratio of 1 stall per 1,000 square feet of manufacturing space and 3.83 stalls per 1,000 square feet of office space. Some of the parking will be located underneath the proposed buildings. The project includes site grading and installation of new utilities and a site drainage system including detention pond, detention vault, and 400 feet of biofiltration swale. The 12.8 acre project site contains areas of Potential Geologic Instability, Class 2. Approximately 9.5 acres of the site will be disturbed by construction activities. The proposed building roofs and uncovered parking facilities will have an area of approximately 8.5 acres; increasing the impervious area of the site by approximately 66 percent. The proposed grading plan will preserve the existing drainage pattem as much as practical. The project site is bounded on the west, north and south by private property and to the east by the Pacific Highway South right -of -way. The site receives runoff from approximately 37 acres located west of the site which is densely developed with single and multifamily homes. Virtually no detention or retention facilities exist upstream of the site. Some stormwater from the upstream area is conveyed to the southern and northem portions of the project site via vegetated ditches. The remaining runoff sheet flows down a steep slope (approximately 20 percent slope) to the west property line. The basin upstream of the site is approximately 37 acres and is densely developed with single and multi - family homes. Stormwater runoff from areas West of Military Road are intercepted by Military Road and therefore is not conveyed to the site. All stormwater from the project site is ultimately collected by an existing storm drain system located in the Pacific Highway South right -of -way. The system consists of interconnected catch basins which drain to the north and discharge via pipes to three locations east of the highway (See Figures 1C through 1E). Some of the stormwater from the site is collected and piped directly to the catch basins in the right -of -way. The remaining stormwater sheet flows off -site to an asphalt swale in the right of way, and is subsequently conveyed northward to the nearest catch basin. Currently, a Type 3 intermittent stream bisects the site as shown on Figure 3B. The stream crosses the Southwest property line and flows to the North and to the East through open ditches and culverts and subsequently discharges to the storm drainage system in the Pacific Highway right -of -way. The stream and the additional sheet flow entering the site from the west will be collected and conveyed to the existing discharge location (Outfall No. 3). This flow, therefore, will bypass the site and will not require retention or detention. The portion of the bypass flow which is less than or equal to the existing 6- month, 24 -hour storm will be routed through a proposed on -site wet pond to enhance water quality, provide a natural habitat for invertebrate, and to provide a small measure of detention. A control structure is proposed which will allow stormwater to bypass the pond when the flow rate exceeds the existing 6- month, 24 hour storm peak runoff rate. Flows above the peak rate will be piped direct to the existing collection system in the right -of way. Since the project will significantly increase the impervious area at the site, detention will be required. Detention system design and analysis is described in Section IV. SECTION II - PRELIMINARY CONDITIONS There are no preliminary approvals associated with this report. On -site soils have been classified as SM and ML in a report prepared by Geotech Consultants, Incorporated, dated March 16,1998. These soils have a moderate runoff potential and can be classified as SCS Hydrologic Soil Group "C". SECTION III - OFF -SITE ANALYSIS A downstream analysis was performed on March 23, 1998, as summarized on the attached "Off -Site Analysis Drainage System Table" and Figure 1D and 1E. Weather conditions during the analysis were overcast with light scattered showers. Several culverts downstream of the project site have submerged inlets and /or outlets and high levels of sediment buildup which may lead to flooding during large storm events. The following excerpt from Page xiii of the "Riverton Stormwater Quality Management Plan - 1997" indicates that the sediment laden culverts under SR599 are a probable cause of existing flooding problems downstream of the site. "There is concern that sediment accumulation has dramatically reduced flood flow capacities of various culvert sections in the lower elevations of the basin (north of South 126th Street). For example, culverts discharging into and across SR 599 are more than half full of sediment. This could contribute to existing flooding at South 126th Street, causing water to backup into the culvert system. It also might result in future flooding at additional sites if flood capacities are not restored. High flow conditions in December 1996 nearly resulted in building flooding at the Boeing complex near 124th Street. Reduced stream channel capacity due to sediment accumulation also is considered a problem at the site. Potential future flooding problems due to continued sediment accumulation in culvert pipes and stream channels is considered the greatest flood issue in the basin." 1 1'. ( c c r (. (. ( ( ( ( (. ( ( J CO • °' w w tr d N UJ V Z_ • �a 0 V± C CO Q2 a Z • 1) W3 Vd `° W o � Subbasin Number. Q Subbasin Name: Riverton Creek Basin/West Tributary Observation of field inspector resource reviewer, or resident • • tributary area, likelihood of problem, • overflow pathways, potential impacts Outfall to Riverton Creek Substantial flow in creek south of outfall Potential Problems cot k.lions, under capacity, ponding overtopping, flooding, habitat or organism destruction, scouring. bank sloughing, sedimentation, inclusion, other erosion a) c z a) c o z a) c z a) c z z a c a) c z a) c a) c Z Existing Problems Minor Siltation c z 0 z c z c z c z Scouring on pond edges 0 z Distance from Site Discharge 1/4 mi = 1.320 ft N CO b 162' -223' 223' -382' 382' -442' 1' EN VQ b CO t� v SO Co O ccoo 880' -1080' O V) $ o CO q 0 10 4 0 (+) N 0 0 N ' r M ■ N ' 0 0 O 0 0 N Drainage Component Description drainage basin, vegetation. cover, depth, type of sensitive area volume Riverton Creek Drainage Basin - West Tributary Asphalt swale along SR99 shoulder 12" RCP between (Type 1 Catch Basin's 112" RCP between Type 1 Catch Basin's 12" RCP between Type 1 Catch Basin's 12" RCP between Type 1 Catch Basin and MH Under SR99 Located in undisturbed area of dense vegetative ground cover Under "Boeing "parking area Drainage Component Type, Name, and Size Type: sheet flow,swale, stream, channel, pipe, pond; size: diameter, surface area Farthest upstream (point, starting at Southeast property (comer Asphalt Swale CB1088 to CB1093 CB1093 to CB1106 CB1016 to CB1010 0 O N_ o O cii U 16" RCP C a° E In a. U °.-o o n E ¢ a a a a a 4 a a a a a a Q a Table 1 of 7 Oi co 0) 4 4 1 4 • (: �js• 'fly 03 C H E • ' w� d � W O U Z �.. i/i } J 0 Q Z s- i• ts cn ( o i ( ( Subbasin Number. m Subbasin Name: Riverton Creek Basin/West Tributary Observation of field inspector • resource reviewer, or resident tributary area, likelihood of problem, overflow pathways, potential impacts Pipe outlets on a 2H:1V slope. Erosion from discharge point to toe of slope. Good water quality feature I Potential Problems constrictions, under capacity, ponding overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, inclusion, other erosion 0 z 0 z 0 z 0 z 0 z 0 z 0 z 0 z Existing Problems Minor Siltation CU 0 z c 0 z � z C 0 C Major Erosion C z Distance from Site Discharge C �N� E r - b ro F- r. 155' -224' N N N �t o O r- O r r 0) O r a) O (n o o t- cV `e h .- \° M T- `e o cci `� 00 cri r- r' o MI `e Lt) O Drainage Component Description drainage basin, vegetation, cover, depth, type of sensitive area, volume Riverton Creek Drainage Basin - West Tributary Asphalt swale along SR99 shoulder 12" RCP between Type 1 Catch Basin's 12" RCP between Type 1 Catch Basin's 12" RCP between Type 1 Catch Basin's 12" RCP between Type 1 Catch Basin's Under SR99 Earthen ditch Dense vegetation, standing water, potential wetland Drainage Component Type, Name. and Size Type: sheet flow,swale; stream, channel; pipe.: pond; size: diameter, surface area r Farthest upstream discharge point, starting at MH1200 Asphalt Swale CB1116 to CB1119 N Til- t) O rn m 0 CB1127 to CB1205 CB1205 to CB1227 24" RCP Steep Ditch Poorly Defined Channel S .o E N a. '° E § m 0.1 m m m et m m CO [n m m m m m CO C m m Table 2 of 7 r c7 (r ( (. (. t Subbasin Number W 4k CO a a CD d • 6. WAS cr } D 8 ca d LU G m V Z a E l0 Z o C (/) C cNo J a z A• S 1- • 8 m LL t o Riverton Creek Basin Vest Tributary Observation of field inspector resource reviewer, or resident tributary area, likelihood of problem, overflow pathways, potential impacts Dense vegetation around inlet and outlet Dense vegetation around inlet and outlet Outfall to Riverton Creek Potential Problems n• capacity, ponding ;, habitat or organism ng, bank sloughing, usion, other erosion O Z .O Z O Z O Z O Z Existing Problems Inlet and outlet submerged c 0 Z Inlet and outlet submerged c 0 Z Inlet submerged, outlet buried Distance from Site Discharge 1 i 0 M . r E ti r- o NI-- N T � �- T 10 N T Nb N T 1275' -1340' o co CO r- °v co T 1380' -1445' O e CV e N \ N \ CV e CV Drainage Component Description drainage basin, vegetation, cover, depth, type of sensitive area, volume. Under "Boeing" parking area Bioswale, potential wetlands, in good condition Under "Boeing" parking area Bioswale, potential wetlands, in good condition Under "Boeing" parking area Drainage Component Type, Name, and Size Type: sheet flow,swale, stream, channel, pipe, pond; size: diameter, surface area 12" CMP m a U ZNi m a 0 r a cn N E 0 T m m T 00 o m r Yl C T. m e B12 -B13 Cm m ( (.. (. (. ( Subbasin Number. U 0j E Z A Riverton Creek BasinlWest Tributary Observation of field inspector I resource reviewer, or resident I, P t Scouring at water level, sedimentation at pipe outlet, adjacent to potential Dense vegetation around inlet and outlet Dense vegetation around inlet and outlet Dense vegetation around inlet and outlet, Outfall to Riverton Creek Potential Problems constrictions, under capacity. ponding - overtopping, flooding, habitat or organism desttnrdion, scouring, bank sloughing, sedimentation. inclusion. other erosion - a) 0 a) Z a) 0 Z a) Z m 0 Z m a) Z a) m 0 ar Z u) Minor Siltation c 0 c Z c 0 Outlet submerged. l Scouring,sedimen Itation Inlet and outlet submerged c 0 Inlet and outlet submerged 0I 0 O1 °D 0) � E Distance from Site Discharge K Q 2 u 0 iA C 265' -375' 375'455' M o) in '0 co c m M 0 8 r co 0 ei IID 0 - ._ poi o . .� N 0 N IIIDD tl1 yt oE p I) i o N Og + ae a o e N + a lV + + N + aks- N i Drainage Component Description 1 1 E. Riverton Creek Drainage Basin - West Tributary Asphalt swale along SR99 shoulder 18" RCP between Type 1 Catch Basin's 18" CMP between Type 1 Catch Basin's Under SR99 Shallow ditch in area of dense ground cover Under "Boeing "parking area Bioswale, potential wetlands, in good condition Under "Boeing-parking area Bioswale, potential wetlands, in good condition Under "Boeing"parking area, trash bars on outlet Drainage Component Type, Name, and Size B. Farthest upstream point, starting at CB1223 to CB1244 to CB1259 CB1259 to CB? 18" PVC Poorly defined ditch 2 U ig g U ig 2 U € 6 Y T ii 0 h OQ YC� 01 - 4�i 1 2 Ci v .o 1 ( (. (. ( (. 4 (. ( W � m - O W W • .7 tr CO ;• 12 W O O U Z L u) c cn C) Q z Q W3 U? a) u �° o � Subbasin Number. Riverton Creek Basin Subbasin Name: Duwamish River Basin m Observation of field inspector resource reviewer, or resident tributary area, kkelibood of problem, overflow pathways, potential impacts Some scouring at waterline in grass lined portions of channel Crushed outlet reduces cross sectional area of pipe by approximately 5% Subbasin B Outfall Tension cracks in asphalt parallel to gabion wall, some currently under repair Erosion on east side of channel near existing hydrant Subbasin C outfall to Riverton Creek Potential Problems overtopping. noourig, rnrxrac a organsm destruction, scouring, bank sloughing, sedimentation, inclusion, other erosion 0 z 0 0 z 0 z 0 0 z z 0 z z 0 z Existing Problems Minor siltation, and scouring Outlet slightly crushed cu c 0 z Gabion wall (failing on east aside of channel I Erosion at D6 Minor sedimentation, scouring Minor sedimentation, (scouring Submerged outlet Distance from Site Discharge e II 'E b o ~ b ...-• 1740' -1810' 1810' -1823' 1823' -2028' 2028' -2150' . N N 2250' -2320' 2320' -2450' d 0 V N + o N + \ N + ez N t \ N + \ N t oe .....(11 a N Drainage Component Description 1 Riverton Creek Drainage Basin - West Tributary 'Combination of rockery, rip -rap, pile/lagging wall,gabion and ecology block stabilization Under parking area access road Grass channel w /gabion stabilization Grass channel w /gabion stabilization Grass channel w /gabion stabilization Grass lined channel, no stabilization, good stand of vegetation Grass Tined channel, no stabilization, good stand of vegetation Under "METRO" parking area, conc headwall w/trash bars on inlet Drainage Component Type, Name, and Size 1, ' 11 11 1 ,t'll H_. Subbasin A outfall Channel with "Hard" Stabilization a. chi Stabilized Channel Stabilized Channel Stabilized Channel Grass Lined Channel Grass lined Channel 42" RCP 0 . ., ;: o CV 0 a 0' 0 o Q o A q 8 g 1. 0 0 m .0 ce- t C.; (. ( ( Subbasin Number. Riverton Creek Basin Subbasin Name: Duwamish River Basin Observation of field inspector resource reviewer, or resident a - .,� Some scouring at waterline in grass Tined portions of channel Crushed outlet reduces cross sectional area of pipe by approximately 5% Subbasin B Outfall Tension cracks in asphalt parallel to gabion wall, some currently under repair Erosion on east side of channel near existing hydrant Subbasin C outfall to Riverton Creek Potential Problems i - 1 •1 I 1 i i ' 1 4. i;i1 . c Z c Z Z c Z c Z Z c Z c c Z • Existing Problems Minor siltation, and scouting Outlet slightly crushed N 0 Z Gabion wall failing on east side of channel Erosion at D6 Minor sedimentation, scouring Minor sedimentation, scouring Submerged outlet Distance from Site Discharge • O r o N. oo O o orD .-- Cr) co M �- 1823' -2028' O r N Nr o to N O (NJ to 2320' -2450' Co CNI t \° N t (a V t N \ t . N t . N t \ N t ° N Drainage Component Description Riverton Creek Drainage Basin - West Tributary Combination of rockery, rip -rap, pile/lagging wall,gabion and :ecology block stabilization ,Under parking area access road Grass channel w /gabion 'stabilization Grass channel w /gabion stabilization Grass channel w /gabion stabilization Grass Tined channel, no stabilization, good stand of vegetation Grass lined channel, no stabilization, good stand of vegetation Under "METRO" parking area, conc headwall w/trash bars on inlet Drainage Component Type, Name, and Size g !Subbasin A outfall Channel with "Hard" (Stabilization a Stabilized Channel Stabilized Channel Stabilized Channel Grass Lined Channel Grass Lined Channel' 42" RCP .13 >. 0 a 0 CO 0 0 o o CO g ( c c t. (. (.. (. (. (. (. (. C ( OFF -SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Subbasin Number. Riverton Creek Basin Subbasin Name: Duwamish River Basin a 0) co Observation of field inspector resource reviewer, or resident tributary area. likelihood of problem. overflow pathways, potential impacts Substantial flow in ditch upstream of confluence (east of headwall). poor water quality w /minor scum Scum accummulation at pipe inlets - Iron oxide and scum present in the surface waters conveyed by ditches running east and west minimal flow in ditch upstream of confluence (east of confluence). poor water quality , w /minor scum upstream. Potential Problems constrictions, under capacity, ponding overtopping. flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, Inclusion, other erosion z z z z z z Existing Problems Minor siltation Submerged outlet Outlet slightly crushed Inlets and outlets !submerged Inlets and outlets submerged Inlets and outlets submerged Distance from Site Discharge .-: II E 2450' -2550' CO N O LO to N N N b ODD N 2920' -3015' ti 0 c1 to O CO N ch b 0 CO a o e CV + e N + z....;.. + e r + e p O e r `+ Drainage Component Description drainage basin, vegetation, cover, j depth, type of sensitive area, volume 100'Wx6'Wx10'Dp concrete channel, aqueous vegetation in bottom Under "METRO" parking area, concrete headwall on outlet Grass swale along SR599, dense ground cover on south side, grass on north Under SR599 access ramp from SR99 Grass vegetated pool w /ditches conveying surface water from the east and west Under SR599 exit ramp to SR99 Drainage Component Type, Name, and Size Type: sheet flow,swale, stream, channel, pipe, pond; size: diameter,. surface area Concrete Channel 42" RCP Wide Grass Swale Dual 48" Culverts Vegetated Poo! Dual 48" Culverts lA a. E 0 o Q Q D p 9 cv (] O 9 Q 9 6 (0 0) .a t t (.- ( .. (- (.. ( ( ( ( Subbasin Number. Riverton Creek Basin Subbasin Name: Duwamish River Basin Observation of field inspector resource reviewer, or resident • tributary area, likelihood of problem, overflow pathways, potential impacts Scouring at water level, parking area to the north drains direct to ditch through wheel stops Scouring at water level, parking area to the east drains direct to ditch through wheel stops Duwamish River Confluence Potential Problems constrictions, under capacity, ponding overtopping, flooding, habiitat or organism destruction, scouring. bank sloughing, sedimentation, inclusion, other erosion c o. Z c c o Z • 0 Z c 0 Z Existing Problems Minor scouring a) c 0 Z Minor scouring Inlets and outlets submerged Distance from Site Discharge 1/4 rni =1.320 ft • 3240' -3835' Cn o ro 01 co co 4085' -4435' in in co 4 0. o ., (n _ ap .. N p O N + N Drainage Component Description 1 drainage basin, vegetation, cover,• depth, type of sensitive area, volume Deep vegetated ditch along SR599, dense ground cover, trees, and grass Sedimentation pond in tidal zone. Gentle grassed slopes on south shore (4H:1 V), Steep slopes (2H:1V) w /dense ground cover on north shore Deep vegetated ditch along SR99, dense ground cover, trees, and grass Under asphalt bicycle/foot path along the Duwamish River Drainage Component Type, Name. and Size Type: sheet flow.swaie; stream, channel, pipe, pond; size: diameter, surface area Vegetated Ditch Sedimentation Pond Vegetated Ditch Dual 48" Culverts ' (n. E.. l S•. D 6 TS C1] 1 15 C� r- r 0 6 r Table 7 of 7 SECTION IV - DETENTION ANALYSIS AND DESIGN The site currently discharges at three locations as previously described. The discharge locations have been identified as Outfalls No. 1 through 3, with Outfall No. 1 being the farthest south and Outfall No. 3 the northern most. (See Figure 3B). The proposed detention system matches the existing flow distribution between the three outfalls as much as practical. Outfall No. 1 will receive undetained runoff from the roof of Building "A ". Runoff to Outfalls No. 2 and 3 will be detained by common facilities which control the discharge through two independent control structures; one serving Outfall No. 2 and the other Outfall No. 3. Detention facilities were designed to provide run -off treatment for the 6- month, 24 -hour design storm event. The streambank erosion control standard limits peak flows, discharged from the developed site to 50 percent of the existing condition 2 -year, 24 -hour event and will maintain the existing condition peak flow rates for the 10 -year and 100 -year, 24 -hour design storms, with appropriate correction factors (see Chapter III -I, SWMMPS). As illustrated in Figure 4, the detention system for Outfalls No. 2 and 3 consists of a wet vault and wet pond. The wet pond is designed to provide water quality to the bypassed off- site flows below the 6 -month storm discharge rates and to serve as additional storage for on -site flows for events greater than the 2 -year, 24 -hour storm. On -site and off -site flows only mix when rainfall exceeds the 2 -year, 24 -hour storm events; when water quality treatment is not required. Therefore, the wet vault is designed to detain the entire 2 -year storm Tess the volume released at a controlled rate to Outfalls No. 2 and 3. A summary of the 6 -month (1/2 the 2- year), 2 -year, 10 -year, and 100 -year, 24 -hour storms for discharges to Outfall No. 1 follows: Outfall No. 1 Return Period Pre Development Post Development 6 -month 0.43 cfs n/a 2 -year 0.86 0.76 cfs 10 -year 1.57 1.17 100 -year 2.53 1.67 As illustrated in the table, Outfall No. 1 does not meet the 6 -month cutoff during the 2 -year storm event. We feel that this is not an issue as the post - development hydrograph is inside the pre - development hydrograph when flows are above the 6 -month cutoff. Therefore, the duration of the post - development peak flows will be equal to or Tess than existing conditions and the duration of high discharge will not be increased or sustained for extended periods of time. In addition, the post - development peak flows will always be less than the pre - development peaks. We feel that the system does meet the intent of Chapter ID of the "Stormwater Management Manual for the Puget Sound Basin ". The proposed total run -off volume is approximately 18% (2,396 cf) less than existing conditions for the two -year storm event. The reduced volume should have minimal impact on downstream water courses. As described in the Downstream Analysis Report, there are no wetlands or habitat areas between Outfall No. 1 of the site and Riverton Creek. Riverton Creek has documented flooding problems and will not be adversely affected by the reduced volume. Spreadsheet output follows. HYDROLOGIC ANALYSIS The performance of the detention facilities was modeled by routing the 2 -year, 10 -year and 100 -year, 24 -hour storms through the facilities. Pre and post development hydrographs were developed using the Santa Barbara Urban Hyrograph (SBUH) method for the SCS Type 1A rainfall distribution. DETENTION SYSTEM The detention system is illustrated and detailed on the "Land Alteration Permit" application Drawings submitted concurrent with this report. The plans show the basic dimensions, orifice /restriction sizes and head relationships, and control structure orientation to the detention facilities. WATER QUALITY Water quality enhancement will be provided for on -site flows via two 200 foot long bioswales and a wet vault. The on -site facilities were designed to provide treatment to the on -site flows up to the 6- month, 24 -hour storm event. Water quality enhancement is also provided for the off -site bypass flows via the on -site wet pond as described previously. Calculations, including all assumptions, are attached to this report. SECTION V - CONVEYANCE SYSTEM ANALYSIS AND DESIGN All permanent run -off conveyance structures were designed to control peak run -off from the 25 -year storm event. Pipe systems were designed to convey and contain at least the peak run -off rate for the 25 -year design storm. Structures for pipe systems will provide a minimum of 0.5 feet of freeboard between the hydraulic grade line and the top of the structure for the 25 year peak rate of run -off. Culverts were designed to convey the peak run -off rate for the 25- year design storm without surcharge. In addition, culverts will convey the 100 -year design storm under surcharged conditions. Drainage ditches and channels were designed to convey at least the peak run -off from the 25 -year design storm with a minimum freeboard to overflow of 0.5 feet. In addition, drainage ditches and channels will convey the peak run -off from the 100 -year design storm without overtopping. All existing and proposed conveyance systems were analyzed and designed using the peak flows from developed hydrographs. Exception: For drainage subbasins less than 25 acres or having a time of concentration of less than 100 minutes, the capacity of conveyance elements were determined using the Rational Method described in Section 4.3.3, KCSWDM. Hydrographs were developed using the Santa Barbara Urban Hydrograph (SBUH) method for the SCS Type 1A rainfall distribution as described in Chapter 3, KCSWDM. CONVEYANCE SYSTEM DESIGN Calculations, including all assumptions, are attached to this report. SECTION VI - SPECIAL REPORTS AND STUDIES Special reports and studies previously required by and submitted to the City of Tukwila include a Geotechnical Report and an On -site Stream Analysis Study. SECTION VII - BASIN AND COMMUNITY PLAN AREAS Site design will be in accordance with the City of Tukwila "Comprehensive Land Use Plan" and "The Surface and Stormwater Management Ordinance No. 1755 ". The site is not located in an area within an adopted Basin Plan, however, the City intends to adopt the "Riverton Creek Stormwater Quality Management Plan" in June or July of 1998. SECTION VIII - OTHER PERMITS There are no other drainage facility permits associated with construction of the proposed project. SECTION IX - TEMPORARY EROSION AND SEDIMENTATION CONTROL ANALYSIS AND DESIGN Temporary Erosion and Sedimentation Control Plans have been included in the "Land Altering Permit" application drawings submitted concurrently with this report. The plan was designed to minimize erosion and the off -site transport of sediments. The plan consists of two phases; • Phase I - Site Clearing and Rough Grading • Phase II - Fine Grading and Paving The main components of the plan include a diversion ditch along the downslope (east) property line in conjunction with temporary sediment traps. Inlet protection will be provided for the existing catch basins in the SR99 right -of -way and on all proposed catch basins upon installation. Erosion control measures include gravel check dams and temporary seeding as the site reaches final grade. L. C. Upon approval of the permit plans, the engineer shall submit to the City of Tukwila the Bond Quantities Worksheet. The design engineer shall separate existing right -of -way and erosion control quantities from other on -site improvements. In addition, the engineer shall total the amounts based on the unit prices listed on the form. Gravel construction entrances may relocate during construction, however, they will be maintained throughout construction. Construction traffic will be limited to one site entrance. Clearing limits will be flagged prior to construction. Sedimentation control facilities will be cleaned as described on the "Land Altering Permit Plans ". SECTION X - BOND QUANTITIES WORKSHEET, RETENTION /DETENTION FACILITY SUMMARY SHEET AND DECLARATION OF COVENANT Bond Quantities Worksheet Retention /Detention Facility Summary Sheet and Sketch C Following approval of the plans, a Retention /Detention Facility Summary Sheet and Sketch shall be submitted along with an 8 -1/2" x 11" plan sketch for each retention /detention facility proposed for construction. 1 L C 1 L L L L C C C. C C C Declaration of Covenant If required by the City of Tukwila, a declaration of covenant as described in Appendix A of King County Ordinance 4938 will be signed and recorded at the office of King County. Records and Elections before any permit with privately maintained retention /detention facilities are approved. SECTION XI - MAINTENANCE AND OPERATIONS MANUAL The owner shall maintain a copy of this report to reference regarding the function of the detention facilities. On -site drainage facilities will be maintained in accordance with Section 1.2.6 and Appendix "A" of the "King County, Washington, Surface Water Design Manual ". Maintenance Manual is included in this report. 1 1 1 1 1 t f (. (. (. { MAINTENANCE OF STORMWA,..:R STRUCTURES rAGE 1 OF 5 PAGES Maintenance Com . ' nent Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed 1. Control Structure Flow Restrictor - Trash & Debris (includes Distance between debris building & All trash & debris removed. General sediment) bottom of orifice is <1 -1/2 feet Structural Damage Structure is not securely attached. to manhole wall & outlet pipe; structure should support at least Structure securely attached to wall and outlet pipe. 1000# of up or down pressure. Structure is not in upright position Structure in correct position. (up to 10% from plumb allowed). Connections to outlet pipe are not watertight & show signs of rust. Connections to outlet pipe are watertight; structure repaired or replaced and works as designed. Any holes - other than designed holes - in structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up & down by one maintenance person. Gate moves up and down easily and is watertight. Chain leading to gate is missing or damaged. Chain is in place & works as designed. Gate is rusted over 50% of its surface area. Gate is repaired or replaced to meet design standards. Orifice Plate Damaged or Missing Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstruction Trash, debris, sediment or vegetation blocking the plate. Plate is free of all obstructions & works as designed. Overflow pipe Obstructions Trash or debris is blocking or potentially blocking the overflow pipe. Plate is free of all obstructions & works as designed. II. Catchbasins - Trash & Debris (includes Trash & debris > 1/211.3 which is No trash or debris immediately General sediment) located immediately in front of the in front of the catchbasin (includes Type 1 & Type 2) catchbasin opening and blocking capacity by > 10 %. opening. Trash or debris in the basin that exceeds 1/4 the depth from the bottom of basin to the invert of the lowest pipe. No trash or debris in the catchbasin. Trash or debris in any inlet or pipe blocking more than 1/8 of its height. Inlet & outlet pipes free of trash or debris, c r (: (.. (.. L MAINTENANCE OF STORM\ . .2;R STRUCTURES PAGE 2 OF 5 PAGES Maintenance Comeonent 4 Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Catchbasins -Gen Cont Dead animals or vegetation that could generate odors or dangerous gases (e.g. methane). No dead animals or vegetation present within the catchbasin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Structural Damage to Corner of frame extends more than Frame is even with curb. Frame and/or Top Slab 3/4 inch past curb face into the street (if applicable). Top slab has holes larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all material is running into the basin). Top slab is free of holes and cracks, Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in Basin Walls or Cracks wider than 1/2 inch and Basin replaced or repaired to Bottom longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. design standards. Cracks wider than 1/2 inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ Basin has settled more than 1 inch or Basin replaced or repaired to misalignment has rotated more than 2 inches out of alignment. design standards, Fire Hazard Presence of chemicals such as natural gas, oil, and gasoline. No flammable chemicals present. Vegetation Vegetation growing across and blocking more than 10% of the basin opening. No vegetation blocking opening to basin. Pollution Nonflammable chemicals of more than 1/2 cubic foot per three feet of basin length. No pollution present other than surface film Catch Basin Cover Cover not in place Cover is missing or only partially in place. Catch basin cover is closed, Any open catch basin requires maintenance. ( (• (. L (. ( ( MAINTENANCE OF STORM W1 _.r.R STRUCTURES ` PAGE 3 OF 5 PAGES Maintenance C_om • • •• nent _ Defect _ Conditions When Maintenance is _ Needed Results Expected When Maintenance is Performed Catch Basins (cont) Locking Mechanism Not Mechanism cannot be opened by one Mechanism opens with proper Working maintenance person with proper tools. Bolts into frame have less than 1/2 inch of thread. tools. Cover Difficult to Remove One maintenance person cannot remove lid after applying 80 lbs. of lift; intent is keep cover from sealing off access to maintenance. Cover can be removed by one maintenance person. Ladder Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Metal Grates Grate with opening wider than 7/8 Grate openings meet design (if applicable) inch. standards. Trash and Debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. Damaged or Missing Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. III. Ponds General Trash & Debris Any trash and debris which exceed 1 cubic foot per 1000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Poisonous Vegetation Any poisonous vegetation which may constitute a hazard to personnel or the public. Examples of poisonous vegetation include: tansy ragwort, poison oak, stinging nettles, devils club. No danger of poisonous vegetation where personnel or the public might normally be. (Coordination with county ' health dept.) Pollution Oil, gasoline, or other contaminants of one gallon or more or any amount found that could: 1) cause damage to plant, animal, or marine life; 2) constitute a fire hazard; or 3) be flushed downstream during rain storms. No contaminants present other than a surface film. (Coordination with county health dept.) Unmowed Grass/Ground Cover The general policy is to make the pond site match adjacent ground cover and terrain as long as there is no interference with the function of the facility, 4 1 MAINTENANCE OF STORMW}, sR STRUCTURES ` -rAGE 4 OF 5 PAGES Maintenance Com r e nent Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Ponds (cont.) Side Slopes of Pond Storage Area Check Dams Emergency Overflow /Spillway IV, Pipes Open Ditches Rodent Holes Insects Tree Growth Erosion Sediment Settlements Rock Missing Sediment & Debris Vegetation Damaged Trash & Debris Any evidence of rodent holes if facility is acting as a dam or Berm, or any evidence of water piping through dam or berm via rodent holes. When insects such as wasps and hornets interfere with maintenance activities. Tree growth does not allow maintenance access or interferes with maintenance activity (i.e., slope mowing, silt removal, vactoring or equipment movements). If trees are not interfering with access, leave trees alone. Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Accumulated sediment that exceeds 10% of the designed pond depth. Any part of dam which has settled 4 inches lower than the design elevation. Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil. Accumulated sediment that exceeds 20% of the diameter of the pipe. Vegetation that reduces free movement of water through pipes. Protective coating is damaged; rust is causing more than 50% deterioration to any part of pipe. Any dent that decreases the cross section area of pipe by more than 20 %. Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch onrl elnrwe Rodents destroyed and dam or berm repaired. (Coordination with county health department). Insects destroyed or removed from site. Trees do not hinder maintenance activities. Selectively cultivate trees such as alders for firewood. Slopes should be stabilized by using appropriate erosion control measure(s); e.g., rock reinforcement, planting of grass, compaction. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Dam should be built back to the design elevation. Replace rocks to design standards. Pipe cleaned of all sediment and debris. All vegetation removed so water flows freely through pipes. Pipe repaired or replaced. Pipe repaired or replaced. Trash and debris cleared from ditches. t I 1 t ( c {.. 1 1 {. MAINTENANCE OF STORMW }_ .. R STRUCTURES I'AGE 5 OF 5 PAGES Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Main is Performed Open ditches (cont) Sediment Vegetation Erosion Damage to Slopes Accumulated sediment that exceeds 20% of the design depth. Vegetation that reduces free movement of water through ditches. See "Ponds" Section III. Ditch cleaned/flushed of all sediment and debris so that it matches design, Water flows freely through ditches, See "Ponds" Section III. Rock Lining Out of Place Maintenance person can see native Replace rocks to design or Missing (if Applicable) soil beneath the rock lining. standard. Debris Barriers (e.g. Trash Racks) General Trash and Debris Trash or debris that is plugging more than 20% of the openings in the barrier. Barrier clear to receive capacity flow. Metal Damaged/Missing Bars Bars are bent out of shape more than 3 inches, Bars are missing or entire barrier is missing, Bars are loose and rust is causing 50% deterioration to any part of barrier, Bars in place with no bends more than 3/4 inch, Bars in place according to design. Repair or replace barrier to design standards. King County Building and Lcc,sd Developmont Division . TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART 1 PROJECT OWNER AND PROJECT ENGINEER ProjeclOwner Sabey Corporation Addressi 2421 .Pacific Hiway South Phone L206) 281 -8700 Project Engineer Bruce Kessler, P.E. Company Nelson - Bourdages Address Phone 512 6th St. S Kirkland W _ph- 425 -827 -5995 fx 425- 828 -4850 . PART 3 TYPE OF PERMIT APPLICATION El Subdivision Fl Short Subdivision C.1 Grading (xi Commercial (—j Other A Page 1 of 2 Figure YEA PART 2 PROJECT LOCATION AND DESCRIPTION Project Name Pacific Location . Township 23N flange Section Project Size AC 12.8 Upstream Drainage Basin Size AC 37 View Office Park 4E 9 PART 4 OTHER PERMITS DOF /G HPA El COE 404 El DOE Dam Safety El FEMA Floodplaln C1 COE Wetlands Q Shoreline Management • ED Rockery Structural Vautis cJ Other ' CI HPA PART 5 SITE COMMUNITY AND DRAINAGE BASIN Community City of Tukwila Drainage Basin Riverton Creek PART 6 SITE CHARACTERISTICS 0 River ® Stream Type 3 to relocate EJ Critical Stream Reath {� Depresslons/Swales 1 =:1 Lake L_1 Sleep Slopes- -- (... I Lakeside /Erosion Hazard LI Floodplain. I—I Wetlands ED Seeps /Springs j_] High Groundwater Table Q Groundwater Recharge -..._ El Other PART 7 SOILS Soil Type ... .. Slopes SCS Group „C _2.5H:1V I , ,...I Additional Shoals Altatched Erosion Potential Moderate to High Erosive Velocities . 4 fps Imn Pngo2of2 fi Kin .ounty Building and Lend Development Division Figure 1B TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART © DEVELOPMENT LIMITATIONS REFERENCE [� Ch, 4 - Dgwnstroam Analysis C1 C7 C1 LJ Additional Sheets Matched LIMITATION /SITE CONSTRAINT See attached , PART 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Sedimentation Facilities Stabilized Construction Entrance Perimeter Runoff Control Clearing and Grading Restrictions Cover Practices Construction Sequence Other MINIMUM ESC REQUIREMENTS " FOLLOWING CONSTRUCTION El. Stabilize Exposed Surface IXi Remove and Restore Temporary ESC Facilities (x�1 Clean and Remove All SIR and Debris Ixl Ensure Oporallon of Permanent Facilities 1�1 Flag Limits of NGPES L� Other aAhT 10 SURFACE WATER SYSTEM E1 Grass Lined Channel (x J Pipo System IJ Open Channel C] Dry Pond Li Wel Pond EJ Tank I.:.I Vault U Energy Dlssapator El Wetland [....J Stream EJ Infiltration rr'I Depression Flow Dispersal [=J Waiver El Regional Detention Method of Analysis Componsatlon/Mlllgallon of Eliminated Site Storage Brief Description of System Operation Site discharge will be restricted to the Ere - develoRed 6 -month (up to 2 year), 10 —year, and 100 —year, 24 —hour storm e Facility Related Silo Limitations LJ Additional Sheets Allatchod Ftolorence Facility LImllntIon PART 11 STRUCTURAL ANALYSIS (May teclutre special structural review) Ef] Cast In Place Vault rN1 Retaining WWI Cl Rockery >4' High cn Structural on Sloop Slope D Olher PART 12 EASEMENTSrt'RACTS Et Drainage Easement EJ Access Easement El Native Growth Protection Easement E] Tract.... ri Other PART 14 SIGNATURE OF PROFESSIONAL ENGINEER I or a civil engineer undor my ouporvision hnvt visited the alto. Actual elle conditions as observed were Incorporatod into this workehoet end the attatchrnonts. To the best of my knowledge the Informallon'provIded here Is accurate. entE 1/h0.- ,..01■1111•1.1111.1.11■11.• 4i. TT RI VER TOV CliEEK" Ikkebtil CONTOUR INTERVAL 25' TOPOGRAPHY DIGITIZED FROM USGS 7.5 MINUTE MAP LEGEND EXISTING CULVERT EXISTING FLOW PATH EXISTING INDEX ELEVATION CONTOUR EXISTING INTERMEDIATE ELEVATION CONTOUR 0 150 APPROMMA7E FIGURE 1 D Cr) LLJ LtJ L) 0 150 300 600 V lam' 0 100 200 400 APPROXIMATE SCALE: 1"=200' EX!SPNG CULVERT EXISTING FLOW PATH EXISTING INDEX ELEVATION CONTOUR EXISTING INTERMEDIATE ELEVATION CONTOUR CONTOUR INTERVAL 25' TOPOGRAPH Y DIGITIZED FROM USGS . 7.5 MINUTE MAP • • • • • • • • • • • • • • • • • • • • 1 0 WO 200 400 APPROXIMATE SCALE: 1"=200' LEGEND EXISTING CULVERT EXISTING FLOW PATH EXISTING INDEX ELEVATION CONTOUR EXISTING INTERMEDJATE ELEVATION CONTOUR CONTOUR INTERVAL = 25' TOPOGRAPHY DIGITIZED FROM USGS 7.5 MINUTE MAP FIGURE 1F '1 r0 a division of Poggemy+er Design Group, Inc. 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STY s S 3501N.:STi, NELSON — BOURDAGES 1998 O 1 512 6th Street South Suite 202 Kirkland, WA 98033 AND SITE LOCATION J425) 827 — 5995 FAX: (425) 828 — 4850 SABEY CORPORATION PACIFIC VIEW OFFICE PARK VICINITY MAP FIGURE 3A Duwanim 99 1 j ■ PROJECT SITE I 1 0 Footb ST M.E NI. n••4 Mh• M, u NELSON - BOURDAGES woe O o division of Poggemyer Design Group, Inc. 512 6th Street South Suite 202 Kirkland, WA 98033 (425) 827 - 5995 FAX: 425 828 - 4850 SA BE Y CORPORATION PACIFIC VIEW OFFICE PARK UPSTREAM BASIN 7.5 MINUTE USGS MAP , SEE FIGURE 3A FOR UPSTREAM BASIN NELSON- BOURDAGES A Division of Popp-now D+d9^ Group, Inc. COPYRIGHT C© i 998 ,EL90N- BOIA1DA 512 6th Street South, Suite 202 *Mond, WA 980,11 (425) 827 - 5995 FAX: (425) 828 - 4850 e -moi: neiabour000Lcom FIGURE 38 FIGURE 3A FOR TREAM BASIN %'" • -, • • ' • • r 1* SITE PLAN 7. � ko. P P 0 125 APPROXIMATE SCALE: 1'1=125' BASIN AREAS DO NOT INCLUDE AREAS TO BE BYPASSED SABEY CORPORATION PACIFIC VIEW OFFICE PARK PRE DEVELOPMENT. DRAINAGE BASIN DELINEATION ••. NELSON- BOURDAGES A Division o( Poggeme}or D.&.i Group, Inc. COPYRIGHT CC 1998 • NELSON— BOURDA 512 6th Street South, Suite 202 Kirkland, WA 98033 (425) 827 - 5995 FAX: (425) 828 - 4850 e -moil: nelabourOool.com FIGURE 3C • OR N • .• / • , ,, ,,,, SBYPAS ED AREA , • •..• •• • •- • • / :-" „ ,••• ,, • .", • • •,,, ,,, • ,, • •••• • , ,,, • ,,, • •-• "::- ';,•%•-:;•••;;, , •'• , --- • ,,,, , ,,,,, „-• 5•;,. , '••■1 , SITE PLAN • 0 125 APPROXIMATE SCALE:. 1=125' SABEY CORPORATION PACIFIC VIEW OFFICE PARK •. POST DEVELOPMENT • • • r■ 1 1 1 1 1 1 II & Ar•1 .1&•11., TV/11 1. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • NOON- Lo co r BIOSWALE .- ...••11 1•.••••• • • ON -SITE FLOW [iXCESS RUNOFF FROM > 2 -YEAR STORM EVENT • OFF -SITE FLOW ENTERS PROPERTY ALL FLOW TO DETENTION FACILITY DETENTION FACILITY 2- YEAR STORM V 6 -MONTH STOR PEAK STAGE (OFF -SITE FLO DEAD STORAGE F WATER QUALITY CONTROL STRUCTURE No- OUTFALL N0. 2 FLOWS COMBINE NELSON- BOURDAGES A Otriion of Pommy" Ooofpn Crow, , Inc, COP!►116117 1996 512 6th Street South, Suite 202 Kirtrlor4 WA 98013 7 - 5995 (425) (425) 828 - 4850 e-mo8 nelebour /ooicom FIGURE 4 ON -SITE FLOW] lidEXCESS RUNOFF FROM > 2 -YEAR STORM EVENT NO YES ALL FLOW TO POND POND 6 -MONTH STORM V EQUALIZATION PIPE 2' DEAD STORAGE FOR WATER QUALITY OUTFACE NO. 3 PACIFIC VIEW OFFICE PARK. SABEY CORPORATION ON -SITE AND OFF -SITE DRAINAGE FLOW CHART PACIFIC VIEW OFFICE PARK DRAINAGE CONTROL PLAN CALCULATIONS I. Objective • Present established guidelines used to design the conveyance and detention structures for this project. 11. Reference • Overall site plan (drawings C1 through C21) • "King County WA, Surface Water Design Manual" (KCSWDM) • "Stormwater Management Manual for the Puget Sound Basin" (SWMMPS) III. Design Criteria Run -off Conveyance Structures: • All permanent run -off conveyance structures were designed to control peak run -off from the 25 -year storm event. • Pipe systems were designed to convey and contain at least the peak run -off rate for the 25 -year design storm. Structures for pipe systems will provide a minimum of 0.5 feet of freeboard between the hydraulic grade line and the top of the structure for the 25 year peak rate of run -off. • Culverts were designed to convey the peak run -off rate for the 25 -year design storm without surcharge. In addition, culverts will convey the 100 -year design storm under surcharged conditions. • Drainage ditches and channels were designed to convey at least the peak run -off from the 25 -year design storm with a minimum freeboard to overflow of 0.5 feet. In addition, drainage ditches and channels will convey the peak run -off from the 100 - year design storm without overtopping. • Temporary erosion control measures were designed to control peak run -off from the 2 -year storm event. Detention Facilities: • Detention facilities were designed to provide run -off treatment for the 6- month, 24 -hour design storm event. The streambank erosion control standard limits peak flows, discharged from the developed site to 50 percent of the existing condition 2- year, 24 -hour event and will maintain the existing condition peak flow rates for the 10 -year and 100 -year, 24 -hour design storms, with appropriate correction factors (see Chapter III -I, SWMMPS). Pacific View Drainage GZ„ iulations IV. Analysis, • All existing and proposed conveyance systems were analyzed and designed using the peak flows from developed hydrographs. Exception: For drainage subbasins 25 acres or less, and having a time of concentration of Tess than 100 minutes, the capacity of conveyance elements were determined using the Rational Method described in Section 4.3.3, KCSWDM. • Hydrographs were developed using the Santa Barbara Urban Hydrograph (SBUH) method for the SCS Type 1A rainfall distribution as described in Chapter 3, KCSWDM. V. Calculations Ditch and Channel Design: A spreadsheet was used to design the ditches and channels in this section. The spreadsheet calculations are based on Manning's equation. Manning's equation can be stated as: 1.486 AR "3S1" Q N Where„ Q = Discharge (cfs) n = Manning's roughness coefficient A = Cross - sectional area of flow (SF) R = Hydraulic radius (ft) which equals the cross - sectional area A divided by the wetted perimeter P S = Channel slope (ft/ft) For trapezoidal applications, the following sketch defines some of the variables: W Nelson - Bourdages a Division of Poggemeyer Design Group, Inc. Pacific View Drainage Cciculafions where, W= top width of flow (ft) B = bottom width of channel (ft), B = 0 for triangular swales Y = depth of flow (ft) M = average side slope ratio = M1 + M2 2 Manning's equation can be rearranged as: AR 2" = Qn 1.49 or, (By *My2) By + My2 _ Qn B +2y)1 +M2 1.49 J It can be seen that if Q, N, S, B and M are known then Y can be found. The spreadsheet calculates Qn ,_. separately calculates AR 2/3 in a data base for 1.494 depths ranging from 0 to 3 feet at 0.01 ft increments. The spreadsheet takes the calculated value of Qn and locates the Y value in the data base which makes 1.49v AR 2i3> Qn This Y value is the normal depth. 1.49 After Y is found for a specific channel design, the design must be checked to ensure that the channel lining will not erode. Therefore the spreadsheet calculates the channel water velocity V and liner shear stress T. carer...,.. c......�.,...... es nr..r..r.... ,.2 Pacific View Drainage kculations These are calculated as: Q 1.49j A n 1?"3 and T = 62.4/b/ ft3 (y)(S) • The following roughness coefficients were used for ditch, channel and culvert calculations Description of Lining Earth 0.022 Grass 0.032 RCP & concrete 0.013 CMP 0.024 Temporary synthetic channel lining 0.032 Allowable ditch and channel velocities are listed below. for earth V max = 2.5 fps for grass, Vmax = 4.5 fps For synthetic liners, refer to manufacturer's specifications for allowable velocities and stresses. Each ditch and channel was checked with the spreadsheet to determine the normal depth, erosion resistance with a temporary earth liner (2 yr. storm) , temporary mat liner (2 yr. storm), and with a healthy stand of grass (25 yr. storm). Culvert Design Calculations: Required pipe diameter (D) in inches were estimated for pipes and culverts using Manning's equation for pipes flowing full with no surcharge. D =16[ Qn] 3/8 Nelson-Bourdages a Division of Poggemeyer Design Group, Inc. Pacific View Drainage c...ulations Detention Facilities Design: A spreadsheet was used to route the 2 year, 10 year and 100 year - 24 hour storms through the detention facilities. Pre - development and post development flows were determined using additional spreadsheets and the SBUH method for the SCS type 1A rainfall distribution. • Outflow from the emergency spillway was calculated with the basic weir equation: Q =C its LH' /2 Cw weir coefficient = 3 for broad crested 3.3 for sharp crested L = Length of weir (ft) H = Driving head (ft) • Outflow from the principle control structure was calculated as the lowest of the following; a) control structure acting as a weir, where, Cw = 3.0 L= 11D(ft) b) control structure acting as an orifice, where, Q =CdA 2gh and, Cd = coefficient of discharge = 0.6 (typical value) A = area of flow through orifice (sf) g = acceleration of gravity = 32.2 ft/s2 h = driving head (ft) • The spreadsheet calculates stage, storage, inflow, and outflow at 10 minute intervals. The incremental change in storage is determined by: ASij = (1i- Oi)ATij Nelson - Bourdages a Division of Poggemeyer Design Group, Inc. 1 Pacific View Drainage CL lations where, = incremental change in storage �^ Ii = Inflow @ time i Oi = outflow @ time i C ATij = 10 minutes Stage - storage was modeled by the following: a) vault V.. = LWS . 1J J ( where„ (., = tank volume (cf) @ time j ( W = tank width L = tank length (. . = stage @ time j b) Pipe from vault to control structure(s) = LA.. = (a— sin acosa)I�d2 ( where„ (. = tank volume @ time j L = pipe length (ft) A. = wetted area (sf) @ time j d = pipe diameter (ft) y = depth of flow in pipe (ft) Cosa =1 -2Y Pond The stage - storage in the pond can be presented by a power curve of the form; Z= (—K Nelson - Bourdages a Division of Poggemeyer Design Group, Inc. s s 0 0 O O 0 0 0 O 0 O 0 0 O O 0 O . 0 0 • 1 r 0 0 Pacific View Drainage Calculations where„ S = storage volume (cf) Z = stage from bottom of the pond Ks and b = constant describing the basin In z S b= S' Z, K = z 2 b Ks and b were estimated with a spreadsheet using linear regression on the In(s) vs In(z). The stage- storage relationship was quantified at 1 -foot intervals as measured using AutoCAD. The inflow /outflow hydrograph and detention facilities spreadsheets were checked for accuracy on numerous occasions using Hyd.exe as developed by King County and with "Water Works ", software for Hydrology, Version 2.9. Nelson - Bourdages a Division of Poggemeyer Design Group, Inc, PIPE NETWORK CALCULATIONS 1 1 1 NELSON - BOURDAGES Page of e division of Poggomeyer Design Group DATE: 07- Jun-98 BY: BEK CHKD BY: JOB 0 980200 I OBJECTIVE PACIFIC VIEW OFFICE PARK Stormwater Pipe Network SIZE ON -SITE PIPES C. II DESIGN CRITERIA PIPES: SIZE FOR 25YR, 24HR STORM W/O SURCHARGE �. SIZE FOR 100 YR, 24HR STORM W/ 0.5' MAX SURCHARGE III METHODOLOGY PEAK INFLOW: PEAK INFLOW WILL BE CALCULATED USING THE RATIONAL METHOD, WHERE PIPES: Qr = CIrA Ir = Pr*(ir) Tc = U60V Qr = PEAK FLOW (cfs) FOR A GIVEN STORM RETURN PERIOD r C = RUNOFF COEFFICIENT, TABLE 4.3.3A, KC DESIGN MANUAL Ir = PEAK RAINFALL INTENSITY (in /fh) FOR A GIVEN RETURN PERIOD r A = AREA OF DRAINAGE BASIN (acres) Pr = TOTAL PRECIPITATION FOR THE DESIGN STORM OF RETURN PERIOD r. (FROM ISOPLUVIAL MAPS) it = (ar)*(Tc)^(-br) ar = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.38) br = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.38) Tc = TIME OF CONCENTRATION (min) WHERE, L = FLOW DISTANCE (ft) V = AVERAGE VELOCITY ACROSS LAND COVER (fps) = Kr(So) ^0.5 Kr = Tc VELOCITY FACTOR (fps), FIGURE 4.3.3B, KC DESIGN MANUAL So = AVERAGE LAND SLOPE (ft/ft) PIPES WILL BE SIZED USING MANNING'S EQUATION FOR PIPES FLOWING JUST FULL; D = 16(Qn /(S) ^2) ^0.375 �. WHERE, Q = FLOW IN CHANNEL (cfs)D = MINIMUM PIPE DIA (in) n = MANNING'S ROUGHNESS COEFFICIENT S = PIPE SLOPE (ft/ft) VELOCITIES IN THE PIPES WILL BE ESTIMATED WITH DARCY'S LAW; c V (fps) = Q/A n.\coocarie 1CC noononf ri 11 VCDT• VI Q f r r r cV C L 1. C 1. C C C C C C C C C C IV CALCULATIONS 25 -YEAR, 24 -HOUR STORM: P25 (in) = 3.4 <= =FROM ISOPLUVIAL MAPS a25 = 2.66 <= =TABLE 4.3.38, KC DESIGN MANUAL b25 = 0.65 <= =TABLE 4.3.3B, KC DESIGN MANUAL K25 = 20 <= =FIGURE 4.3.3C, KC DESIGN MANUAL PIPE ID AREA (ac) C Tc 125 Q25 n SLOPE DIA (min) (MR) (In) J 0.018 0.90 0.30 2.73 0.05 0.024 0.020 2.58 K 0.158 0.90 6.30 2.73 0.38 0.024 0.030 5.33 L 0.320 0.90 6.30 2.73 0.79 0.024 0.030 6.97 M 0.546 0.90 6.30 2.73 1.34 0.024 0.030 8.52 N 0.665 0.90 6.30 2.73 1.64 0.024 0.030 9.17 T 0.046 0.90 6.30 2.73 0.11 0.024 0.010 4.14 S 0.148 0.90 6.30 2.73 0.36 0.024 0.010 6.42 R 0.312 0.90 6.30 2.73 0.77 0.024 0,010 8,49 Q 0.460 0.90 6.30 2.73 1.13 0.024 0.020 8,62 p 0.669 0.90 6,30 2.73 1.85 0.024 0.020 9.92 O 0.819 0.90 6,30 2.73 2.01 0.024 0.020 10.70 AR 1.944 0,90 8.30 2.73 4.78 0.024 0,271 9.08 BH 1.944 0.90 6.30 2.73 4.78 0.024 0.020 14.80 AX 2.053 0.90 6.30 2.73 5.05 0.024 0.020 15.10 AY 0.038 0.35 8.30 2.73 0.04 0.024 0.227 1,51 AS 0.154 0.85 6.30 2.73 0.38 0.024 0.085 4.27 AJ 0.303 0.90 8.30 2.73 0.75 0.024 0.018 7.73 AU 0.075 0.90 8.30 2.73 0,18 0.024 0.010 4.96 AZ 0.038 0.35 6,30 2.73 0.04 0.024 0,183 1.57 AT 0.172 0.80 6.30 2.73 0.28 0.024 0.020 5,12 M 0,940 0.40 8,30 2.73 1.03 0.024 0.020 8.31 AB 1.015 0.90 6.30 2.73 2.50 0.024 0.020 11.59 AC 1.130 0.90 6.30 2.73 2,78 0.024 0,025 11.58 AD 1.371 0,90 8.30 2.73 3.37 0.024 0.020 12.98 AE 1.778 0.90 6,30 2.73 4.37 0.024 0.020 14.31 AQ 1.778 0,90 8.30 2.73 4.37 0.024 0.020 14.31 AH 0.025 0.90 6.30 2.73 0.06 0.024 0.012 3.18 AG 0.084 0.90 8.30 2.73 0.16 0.024 0.012 4.51 BJ 0.449 0.98 6.30 2.73 1.20 0.024 0.010 10.04 AF 0.840 0.90 6.30 2.73 2.07 0.024 0.020 10.80 Al 0.840 0.90 6.30 2.73 2.07 0,024 0.018 11.05 AK 2.358 0.90 6.30 2.73 5.80 AL 2.592 0.90 6.30 2.73 6.38 AO 0.048 0.90 6.30 2.73 0,12 AN 0.424 0.90 8.30 2.73 1.04 H 0.071 0.90 6.30 2.73 0.18 I 0.134 0.90 6,30 2.73 0.33 BG 0.205 0.90 6.30 ✓ 0.323 0.90 6.30 W 0.405 0.90 6.30 X 0.456 0.90 6.30 Y 0.456 0.90 8.30 Z 0.715 0.90 8.30 U 1.210 0.40 81 0.762 0.98 BK 0.449 0.98 DASPREADSHEETV/8020C1CULVERT1.XLS 6.30 6.30 8.30 2.73 2.73 2.73 2.73 2.73 2.73 2.73 2.73 2.73 0,50 0.80 1.00 1,12 1.12 1.76 1.32 2.04 1.20 0,024 0.015 18.78 0,024 0.015 17.40 0,024 0.222 2,36 0,024 0.020 0.024 0.020 4.28 0,024 0.048 4.84 0.024 0.073 4.99 0.024 0.115 5.44 0.024 0.100 8.08. 0.024 0.020 8.59 0.024 0.020 8.59 0.024 0.020 10.17 0.024 0.020 9.14 0.024 0.020 10.75 0.024 0.020 8.81 1 1 1 1 1 1 t 100 -YEAR, 24 -HOUR STORM: P100 (In) = 4.03 a100= 2.61 b100 = 0.63 K100 = 20 PIPE ID AREA (ac) <= =FROM ISOPLUVIAL MAPS <= =TABLE 4.3.38, KC DESIGN MANUAL < ==TABLE 4.3.38, KC DESIGN MANUAL < == FIGURE 4.3.3C, KC DESIGN MANUAL C Tc 1100 0100 n SLOPE DIA (min) (ft/ft) (in) .1 0.018 0.90 6.30 3.30 0.05 0.024 0.020 2.76 K 0.156 0.90 6.30 3.30 0.46 0.024 0.030 5.71 L 0,320 0.90 6.30 3.30 0.95 0.024 0.030 7.48 M 0.546 0.90 6.30 3.30 1.62 0.024 0.030 9.14 N 0.665 0.90 6.30 3.30 1.97 0.024 0.030 9.84 T 0.046 0.90 6,30 3,30 0,14 0.024 0.010 4.44 S 0.148 0.90 6.30 3.30 0.44 0.024 0.010 6.89 R 0,312 0.90 6.30 3.30 0.93 0.024 0.010 9.11 O 0.460 0.90 6,30 3.30 1.36 0.024 0.020 9.24 P 0.669 0.90 6.30 3.30 1.99 0.024 0.020 10.64 O 0.819 0.90 6.30 3.30 2.43 0.024 0.020 11.48 AR 1.944 0.90 6.30 3.30 5.77 0.024 0.271 9.74 BH 1.944 0.90 8.30 3.30 5.77 0.024 0.020 15.88 AX 2.053 0.90 6.30 3.30 8.09 0.024 0.020 16.20 AY 0.038 0.35 6.30 3.30 0.04 0.024 0.227 1.62 AS 0.154 0.85 6.30 3.30 0.43 0.024 0.065 4.58 AJ 0.303 0.90 6.30 3.30 0.90 0.024 0.016 8.30 AU 0.075 0.90 6.30 3.30 0.22 0.024 0.010 5.32 AZ 0.038 0.35 6.30 3.30 0.04 0.024 0.183 1.68 AT 0.172 0.60 6.30 3.30 0.34 0.024 0.020 5.50 M 0.940 0.40 6.30 3.30 1.24 0.024 0.020 8.92 AB 1.015 0.90 6.30 3.30 3.01 0.024 0.020 12.44 AC 1.130 0.90 6.30 3.30 3.36 0.024 0.025 12.42 AD 1.371 0.90 6.30 3.30 4.07 0.024 0.020 13.93 AE 1.778 0.90 6.30 3.30 5.28 0.024 0.020 15.35 AO 1.778 0.90 6.30 3.30 5.28 0.024 0.020 15.35 AH 0.025 0.90 8,30 3.30 0.07 0.024 0.012 3.41 AG 0.064 0.90 6.30 3.30 0.19 0.024 0.012 4.84 t 13.1 0.449 0.98 8.30 3.30 1.45 0.024 0.010 10.77 AF 0.840 0.90 8,30 3.30 2.49 0.024 0.020 11.59 Al 0.840 0.90 6.30 3.30 2.49 0.024 0.018 11.86 AK 2.356 0.90 6.30 3.30 7.00 0.024 0.015 18.01 AL 2.592 0.90 6.30 3.30 7.70 0.024 0.015 18.66 C AO 0.048 0.90 6.30. 3.30 0.14 0.024 0.222 2.53 AN 0.424 0.90 8.30 3.30 1.26 0.024 0.020 8.97 C C t H 0.071 0.90 6.30 3.30 0.21 0.024 0.020 4.59 I 0.134 0.90 8.30 3.30 .0.40. 0.024 0.046 4.98 BG 0.205 0.90 6.30 3.30 0.61 0.024 0.073 5.35 ✓ 0.323 0.90 8.30 3.30 0.98 0.024 0.115 5,84 W 0.405 0.90 8.30 3,30 1.20 0.024 0.100 8,52 X 0.456 0.90 8.30 3.30 1.35 0.024 0.020 9.21 Y 0.456 0.90 6.30 3.30 1.35 0.024 0.020 9.21 Z 0.715 0.90 6.30 3.30 2.12 0.024 0.020 10.91 U 1.210 0.40 6.30 3.30 1.60 0.024 0.020 9.81 01 0.762 0.98 6.30 3.30 2.46 0.024 0.020 11.53 BK 0.449 0.98 6.30 3.30 1.45 0.024 0.020 9,46 ADDITIONAL PIPES AT 100 -YEAR, 24-HOUR STORM: G A THROUGH E AW AP AK AL AV BF DASPREADSHEE71980200CULVERT1. XLS 6.30 3.30 23.88 0.024 0.087 20.50 6.30 3.30 31.00 0.024 0.020 6,30 3.30. 2.86 0.024 0.020 6.30 3.30 2.86 0.005 0.209 6.30 3.30 1.70 0.024 0.020 6.30 3.30 1.70 0.024 0.020. 6.30 3.30 6.44 0.024 0,020 6.30 3.30 6.44 .: 0.024 0.130 29.82 12.20 4.36 10.03 10.03 16.54 11.65. OPEN CHANNEL CONVEYANCE CALCULATIONS (. NELSON - BOURDAGES Page of a division of Popgemeyer Design Group DATE: 08- Jun-98 BY: BEK CHKD BY: JOB # 98020C I OBJECTIVE PACIFIC VIEW OFFICE PARK Northeast Swale SIZE BYPASS SYSTEM SWALE FROM PIPE "U" TO STRUCTURE "6" II DESIGN CRITERIA CHANNELS: SIZE FOR 25YR,24HR STORM W/ 0.5' FREEBOARD SIZE FOR 100 YR, 24HR STORM WITHOUT OVERTOPPING III METHODOLOGY PEAK INFLOW: OPEN CHANNEL: PEAK INFLOW WILL BE CALCULATED USING THE RATIONAL METHOD, WHERE Qr = CIrA Qr = PEAK FLOW (cfs) FOR A GIVEN STORM RETURN PERIOD r C = RUNOFF COEFFICIENT, TABLE 4.3.3A, KC DESIGN MANUAL Ir = PEAK RAINFALL INTENSITY (in/fh) FOR A GIVEN RETURN PERIOD r A = AREA OF DRAINAGE BASIN (acres) Ir = Pr"(ir) Pr = TOTAL PRECIPITATION FOR THE DESIGN STORM OF RETURN PERIOD r. (FROM ISOPLUVIAL MAPS) it = (ar)*(Tc)^(-br) ar = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.3B) br = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.3B) To = TIME OF CONCENTRATION (min) Tc = L/60V WHERE, L = FLOW DISTANCE (ft) V = AVERAGE VELOCITY ACROSS LAND COVER (fps) = Kr(So) ^0.5 Kr = Tc VELOCITY FACTOR (fps), FIGURE 4.3.3B, KC DESIGN MANUAL So = AVERAGE LAND SLOPE (ft/ft) OPEN CHANNELS WILL BE SIZED USING MANNING'S EQUATION; Q = (1.49 /n) *AR^2 /3So ^0.5 WHERE, Q = FLOW IN CHANNEL (cfs) n = MANNING'S ROUGHNESS COEFFICIENT A = AREA OF FLOW IN CHANNEL (sf) R = HYDRAULIC RADIUS (ft) So = CHANNEL SLOPE (ft/ft) n.\c nnr A ne. urr., \C\AIA1 • VELOCITIES IN THE CHANNEL WILL BE ESTIMATED WITH DARCY'S LAW; V (fps) = Q/A LINER STRESS IS ESTIMATED AS; T = 62.4YSo WHERE, T = SHEAR STRESS (psf) Y = DEPTH OF FLOW IN CHANNEL (ft) So = CHANNEL SLOPE (ft/ft) IV CALCULATIONS 25-YEAR, 24-HOUR PEAK INFLOW: AREA (acres) = 1.58 C= 0.40 L (ft) = 880 So (ft/ft) = 0.12 K25 = 15 P25 (in) = 3.4 a25 = 2.66 b25 = 0.65 Tc (min)= 6.3 125 (in/hr) = 2.73 Q25 (cfs) = OPEN CHANNEL: Q(cfs) = 1.7 S (ft/ft) = 0.1200 n= 0.035 B(ft) = 0 M = 3 CHANNEL VELOCITY V(ftls) = Q/A = LINER SHEAR STRESS T(Ibtft^2) = )1.73 1 <===GRASS <==TABLE 4.3.3A, KC DESIGN MANUAL <==FIGURE 4.3.3C, KC DESIGN MANUAL <==FROM ISOPLUVIAL MAPS <==TABLE 4.3.3B, KC DESIGN MANUAL <==TABLE 4.3.3B, KC DESIGN MANUAL AR^2/3 = nQ/1.49sA2 nQ/1.49s^2 = 0.12 f(M,y,B) = ARA2/3 = y(ft) NORMAL DEPTH im 0.12 2.70 n•tmoncenewconann/nmetruAi rni n 100 -YEAR, 24 -HOUR PEAK INFLOW: AREA (acres) = 1.58 C= 0.4 L (ft) = 880 So (ft/ft) = 0.12 K100 = 20 P100 (in) = 4.03 a100 = 2.61 b100= 0.63 Tc (min)= 6.3 1100 (in/hr) = 3.30. Q100 (cfs) = OPEN CHANNEL: LINING: CONCRETE Q(cfs) = 2.08 S (ft/ft) = 0.12 n = 0.035 B(ft) = 0 M =3 CHANNEL VELOCITY V(ft/s) = alia.1111111111 4.57 LINER SHEAR STRESS T(Ib/ft ^2) = 2.92 <= =TABLE 4.3.3A, KC DESIGN MANUAL < == FIGURE 4.3.3C, KC DESIGN MANUAL <= =FROM ISOPLUVIAL MAPS <= =TABLE 4.3.3B, KC DESIGN MANUAL <= =TABLE 4.3.3B, KC DESIGN MANUAL AR ^2/3 = nQ/1.49s ^2 nQ /1,4902 = <===GRASS f(M,y,B) = AR ^2/3 = Y(ft) _ 0.14 0.15 rs.tonnrencturr■ nteuIAI rA4 VI r NELSON - BOURDAGES a division of Poggemeyer Design Group t PACIFIC VIEW OFFICE PARK North Runon Diversion System Page of DATE: 26-May-98 BY: BEK CHKD BY: JOB # 98020C I OBJECTIVE SIZE BYPASS SYSTEM CHANNELS AND PIPES FOR THE NORTH SUBBASIN II DESIGN CRITERIA CHANNELS: SIZE FOR 25YR,24HR STORM W/ 0.5' FREEBOARD SIZE FOR 100 YR, 24HR STORM WITHOUT OVERTOPPING i.. PIPES: SIZE FOR 25YR, 24HR STORM W /2' MAX SURCHARGE SIZE FOR 100 YR, 24HR STORM W /SITE SPECIFIC ALLOWABLE SURCHARGE III METHODOLOGY �V PEAK INFLOW: PEAK INFLOW WILL BE CALCULATED USING THE RATIONAL METHOD, WHERE Qr = CIrA L Ir = Pr"(ir) (_ t Tc = U6OV OPEN CHANNEL: Qr = PEAK FLOW (cfs) FOR A GIVEN STORM RETURN PERIOD r C = RUNOFF COEFFICIENT, TABLE 4.3.3A, KC DESIGN MANUAL Ir = PEAK RAINFALL INTENSITY (in/fh) FOR A GIVEN RETURN PERIOD r A = AREA OF DRAINAGE BASIN (acres) Pr = TOTAL PRECIPITATION FOR THE DESIGN STORM OF RETURN PERIOD r. (FROM ISOPLUVIAL MAPS) it = (ar)*(Tc)^( -br) ar = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.3B) br = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.3B) Tc = TIME OF CONCENTRATION (min) WHERE, L = FLOW DISTANCE (ft) V = AVERAGE VELOCITY ACROSS LAND COVER (fps) = Kr(So) ^0.5 Kr = Tc VELOCITY FACTOR (fps), FIGURE 4.3.3B, KC DESIGN MANUAL So = AVERAGE LAND SLOPE (ft/ft) OPEN CHANNELS WILL BE SIZED USING MANNING'S EQUATION; Q = (1.49 /n)"AR^2 /3So ^0.5 WHERE, Q = FLOW IN CHANNEL (cfs) t n.tooenneuee•nnonon•tovoneenA w n = MANNING'S ROUGHNESS COEFFICIENT A = AREA OF FLOW IN CHANNEL (sf) R = HYDRAULIC RADIUS (ft) So = CHANNEL SLOPE (ft/ft) VELOCITIES IN THE CHANNEL WILL BE ESTIMATED WITH DARCY'S LAW; V (fps) = Q/A LINER STRESS IS ESTIMATED AS; T= 62.4YSo WHERE, T = SHEAR STRESS (psf) Y = DEPTH OF FLOW IN CHANNEL (ft) So = CHANNEL SLOPE (ft/ft) IV CALCULATIONS 25 -YEAR, 24-HOUR PEAK INFLOW: AREA (acres) = 10,6 C = 0.60 L (ft) = 250 So (ft/ft) = 0.03 K25 = 15 P25 (in) = 3.4 a25 = 2.66 b25 = 0.65 Tc (min)= 6.8 125 (in/hr) = 2.60 Q25 (cfs) = OPEN CHANNEL: Q(cfs) = 16.5 S (ft/ft) = 0.0260 n = 0.013 B(ft) = 2.5 M =0 CHANNEL VELOCITY V(ft/s) = Q/A = LINER SHEAR STRESS T(Ib/ft ^2) = 16.55 10.34 1.04 n.\coocenCUCCTann9nr10voeCent VI c <= =TABLE 4.3.3A, KC DESIGN MANUAL < == FIGURE 4,3.3C, KC DESIGN MANUAL < = =FROM ISOPLUVIAL MAPS <= =TABLE 4.3.3B, KC DESIGN MANUAL <= =TABLE 4.3.3B, KC DESIGN MANUAL ARA2/3 = nQ/1.49s ^2 nQ /1.49s ^2 = 0.90 <= =CONC. f(M,y,B) = AR ^2/3 = y(ft) r NORMAL DEPTH se 0.90, 100 -YEAR, 24 -HOUR PEAK INFLOW: AREA (acres) = 10.6 C = 0.6 L (ft) = 250 So ( ft/ft) = 0.03 K100 = 20 P100 (in) = 4.03 a100 = 2.61 b100 = 0.63 Tc (min)= 6.8 1100 (in/hr) = 3.14 Q100 (cfs) OPEN CHANNEL: LINING: CONCRETE Q(cfs) = 20.00 S (ft/ft) = 0.025974026 n = 0.013 B(ft) = 2.5 M =0 CHANNEL VELOCITY V(ft/s) = LINER SHEAR STRESS T(Ib/ft ^2) = <= =TABLE 4.3.3A, KC DESIGN MANUAL < == FIGURE 4.3.3C, KC DESIGN MANUAL <= =FROM ISOPLUVIAL MAPS <= =TABLE 4.3.38, KC DESIGN MANUAL. <= =TABLE 4.3.38, KC DESIGN MANUAL AR ^2/3 = nQ /1.49s ^2 nQ /1.4902 = <= =CONC. ` f(M,y,B) = AR ^2/3 = y(ft) = 1.08 1.09 0.73 1.18 fl• \CDii=AnciicpTGstn9nn AVDnnQng YI !C is Dams 1 n /.Z-: NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK South Runon Diversion System 26 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 3.4 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 544,500 12.500 85 IMPERV AREA (sf) = 544,500 12.500 98 Length (ft) = 2,000 Height (ft) = 200 tc (min) = 7 INFLOW ' Qp (cfs) = 16.4 Qp (gpm) = 7,383 Tp (min) = 7.67 VOLUME (cf) = 231,161 Page of DATE: 26- May -98 BY: BEK CHKD BY: JOB # 98020C 18,0000 16.0000 in 14.0000 16 12.0000 ILI 10,0000 8.0000 6.0000 4.0000 2,0000 0.0000 0 0 0 INFLOW INFLOW 0 0 0 S lV w r r TIME (HOURS) fla ehr A nOUC C99nonnnntncvo or• VI c NELSON - BOURDAGES a division of Poggemeyor Design Group PACIFIC VIEW OFFICE PARK South Runon Diversion System 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 544,500 12.500 85 IMPERV AREA (sf) = 544,500 12.500 98 tc (min) = 6.8 INFLOW Qp (cfs) = 20,3 Qp (9Pm) = 9,126 Tp (min) = 7.67 VOLUME (cf) = 284,836 Page of DATE: 26- May -98 BY: BEK CHKD BY: JOB # 98020C 25.0000 20.0000 m LL W 15.0000 0 0C z 10.0000 5.0000 0.0000 0 0 0 INFLOW INFLOW o 0 g N co c3 TIME (HOURS) 5 _ eat 1 of 1.' 1 1 1 1 1 1 1 l l NELSON - BOURDAGES a division of Poggemeyer Design Group' PACIFIC VIEW OFFICE PARK South Runon Diversion System NORMAL DEPTH CALCULATIONS 25 -YEAR, 24 -HOUR STORM LINING: CONCRETE Q(cfs) = 16.4 S (ft/ft) = 0.02 n = 0.013 B(ft) = 2.5 M =0 CHANNEL VELOCITY. V(ft/s) = LINER SHEAR STRESS Page of DATE: 26- May -98 BY: BEK CHKD BY: JOB # 98020C AR ^2/3 = nQ/1.49s ^2. nQ/1.49s ^2 = Y(ft) = f(M,y,B) = ARA2/3 = Normal Depth(ft) _ 1.012 0.70 1,026 0.7 9.37 T(ib/ft^2) = f.tQDDCAf taut GCTGRMftftiQ t1ir tiJAfiuncor YI C • itfl DIU • NELSON- BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK South Runon Diversion System NORMAL DEPTH CALCULATIONS 100 -YEAR, 24-HOUR STORM LINING: CONCRETE Q(cfs) = 20,3 S (ft/ft) = 0.02 n = 0.013 B(ft) = 2.5 M =0 CHANNEL VELOCITY V(ft/s) 10.02 LINER SHEAR STRESS T(Iblft^2) = 1.01 Page of DATE: 26- May -98 BY: BEK CHKD BY: JOB # 98020C AR ^213 = nQ /1.49s ^2 nQ /1.4902 = y(ft) = f(M,y,B) = AR ^2/3 = Normal Depth(ft) = 1 251 1.261 111111li� • A.■ 01[112C A MC/LAC CCTIAOn,.1,. . nIT&'LALI/1EI•IIt T9 VI C • L•lllA11 ;Aft n•• BYPASS DIVERSION CONTROL CALCULATIONS FIGURE 1 SABEY CORPORATION NELSON — ROVRDAGES f900 © PACIFIC VIEW OFFICE PARK o division of Poggemyer Design Croup, Inc, 512 61h Street South Suite 202 UPSTREAM BASIN Kirklond, WA 98033 7, 5 MINUTE USGS MAP (425) 827 — 5995 FAX: (425) 828 — 4550 NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK BYPASS FLOW 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 801,504 18.400 85 IMPERV AREA (sf) = 801,504 18.400 98 Length (ft) = 2,000 Height (ft) = 200 tc (min) = 6.3 INFLOW Qp (cfs) = 30.3 Qp (gpm) = 13,599 Tp (min) = 7.67 VOLUME (cf) = 419,278 Page of DATE: 08- Jun-98 BY: BEK CHKD BY: JOB # 98020C 35,0000 T 30.0000 LL 25.0000 n 20.0000 gC 15.0000 10.0000 5.0000 INFLOW INFLOW 0.0000 8 0 S lV TIME (HOURS) D:ISPREADSHE.EET\98020C1 100BPSTM.XLS 11 :35 PM. Obiective - Design flow control structures to route all bypass flow equal to or less than the existing 6- month, 24 -hour storm inflow rate through the on -site wet pond. Flows greater than the 6- month, 24 -hour storms and equal to or less than the 100 -year, 24 -hour storm will bypass the pond and discharge directly to Outfall No. 1. IL Calculations • The existing 6 -month (1/2 the 2 -year storm) and 100 -year flows were calculated with a spreadsheet using methods described in earlier sections. • From the attached figure, the flow into the pond will equal the flow out, for the 6 -month storm if H1 = H2. • Flow in will equal flow out for the 100 -year storm if H1 = t t c f (. NELSON-BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827-5995 • FAX (425) 828-4850 Made by eey... Date 6 Her s Job No, 9 9 ozoc, Checked by Date Sheet No, 7..., Description 511TO-k-k w 11,-IVIL. 0....,Me_de Job Name A,, _ PiNe...s, <.;kt STVM 0 6 • • • • • • • • • • • • • Q7 CS A ZaN NELSON - BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by ,(� Date /',� 1� Job No. Q$ vZoC. Sheet No. 3 Checked by Date�o - Description Job Name (■`\ PASS S`t `r'\ 5\ IL. O t\ f \ cc To Act,% PRAM Po ty7 f-&2 6 MD N.1-1-1 FLO .k) C Q = e'6 \2,' APE Q : %G4s • • • • • • • • C • • • • • Lo -Is 5'4%a o‘ SA A- Cµ 0P z (Co l 3 AS % .),s\C0,7 6 OA. HAb o•ti la fvc 6` 4.L»W 'CD ANn M Odribh icy 100 ire SCUt.frt, l� = 3. 'Vb % k- o;`l ‘ 4, o,)` Q = o.sl (0t16s4) j G4,4 (A,tg = b ,`k`t as Q0,&(PASS : - 6,4t41. 's c L3, 8b c .v (j tvo, 3 • CAkCLx. • Q C,,,, 1^ • c,,j= 3.O • Cttl w a% bo '4' SMto i•\� N11�c \11 r0 ,S 401A 2.3,3 - 0,jo S Ow'c(o,1 See AC:Tt N.C., ; AS A Walk: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 s �E e�s�e. wor.►b -to -s-cr-vccor4Z 4q 1 NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 8275995 • FAX (425) 828.4850 Made by e.y.._ Date V-119 b Job No, q O Zoe Checked by Date Sheet No. Description Job Name L 23.30 3.o ( 0,1)311 L = 2 T' f Vii) J___1 15.551 432 'Te Y it 8„ e eel. C w = 3,-6 4--- SNA ().-y (sites-nib wev.R- \3.58\ s 1. e "1 2/3 7(3 Z3.8io 3,3 C ‘a,S1)) it jr( o; G 9 Z `4~" �3 sHV ..c cc 0,10 & r.tS'2Q 1 1 1 1 1 1 1 1 1>= • 3.33. (3 3Xd lY/Z 3.3.3 = 1 t 0C, -P+ t-\_ AtA\i US; 1 g v21S r, Poty DETENTION FACILITIES CALCULATIONS II. Obiective - Size the detention facilities as described in the TIR. Calculations • A spreadsheet was used to route the storm through the detention facilities. • Spreadsheet printout follows: NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK POST- DEVELOPMENT SUMMARY: ONSITE DATE: 07- Jun -98 BY: BEK CHKD BY: JOB # 98020C AREA (sf) AREA (acres) CN PERV AREA (sf) = 79,200 1.818 85 IMPERV AREA (sf) = 339,605 7.796 98 tc (min) = 6.3 DETENTION VAULT: POND: LENGTH (ft) = 200 WIDTH (ft) = 25 VOLUME CORRECTION FACTOR = 40% CONTROL STRUCTURE TO OUTFALL NO. 3 PIPE FROM VAULT TO CONTROL MH: DIAMETER (in) = 36 LENGTH (ft) = 20 PIPE IE = 82.2 POND IE = 84 EQ PIPE IE = 87.9 Ks = 666 b = 1.63 OUTLET IE = 82.2 ORIFICE NO 1 EL = 81.2 OR NO 1 DIA (in) = 1.93 ORIFICE NO 2 EL = 87,90 ORIFICE NO 2 DIA (in) = 8.36 OVERFLOW EL = 90 OVERFLOW DIA = 12 (in) RETURN PEAK DISCHARGE PERIOD PRE - DEVELOPMENT POST- DEVELOPMENT (cis) (cfs) 6 MONTH 0,232 2 YEAR 0.464 0.232 10 YEAR 0.980 0.370 100 YEAR 1.699 1.697 PEAK STAGE PEAK STORAGE REQUIRED .W /FACTOR (d) (d). 87.83 20,330 87.98 21,012 88.53. 24.047 D :\SPREADSH. EET198020C1OUTFALL3 \(PVPOND3.XLWJ$UMMARY CONTROL STRUCTURE TO OUTFALL NO. 2 PIPE FROM VAULT TO CONTROL MH: DIAMETER (in) = 36 LENGTH (ft) = 20 PIPE IE = 82.2 OUTLET IE =. 82.2 ORIFICE NO 1 EL = 81.2 OR NO 1 DIA (in) = 2.52 ORIFICE NO 2 EL = 87.90 ORIFICE NO 2 DIA (in) = 10.84 OVERFLOW EL = 90 OVERFLOW DIA = 18 (in):: RETURN PEAK DISCHARGE PEAK PEAK STORAGE PERIOD PRE- DEVELOPMENT POST - DEVELOPMENT STAGE REQUIRED W/FACTOR (cis) (cfs) (ci) (cf) 6 MONTH 0.396 2 YEAR 0.791 .0.396 87.83 20,330 28,462 10 YEAR 1.656 0.576 87.98 21,012 29,416 100 YEAR 2.859 2.859 88.53 24,047 33,666 DA SPREA DSH .EE1198020C\OUTFALL311PVPOND3 XLWj8UMMA f a division of Poggemeyer Design Group 1 ( STAGE- STORAGE CALCULATIONS f (. (. REGRESSION OUTPUT hisgressioa Statistics (/. 1�. NELSON - BOURDAGES PACIFIC VIEW OFFICE PARK DETENTION POND Page of DATE: 25- Mey -98 BY: BEK CHKD BY: JOB M 98020C ELEV AREA VOLUME ACC. STAGE LnS LnZ (sf) (cf) (Gf) (ft) S Z 184 514 0 0 185 931 723 723 186 1,451 1,191 1,914 187 2,078 1,765 3,678 188 2,800 2,439 6,117 189 3,612 3,206 9,323 190 4,513 4,063 13,386 Multiple R 0.997666 R Square 0.995338 Adjusted R Squa 0.994172 Standard Error 0.082464 Observations Analysis of F'arianuE, Regression Residual Total 6 0 1 2 3 4 5 6 b = 1.63 Ks = 666 df Sua of arms Mean •mare 1 5.00716086 5.80716086 4 0.027200916 0.006800229 5 5.834361776 Coefficients Standard Error 0.00 0.00 6.58 0.00 7.56 0.69 8.21 1.10 8.72 1.39 9.14 1.61 9.50 1.79 F ificance F t Statistic 853.9654946 8.164E -06 F. -value .Lover 95* Upper 95* Intercept 6.501714 0.069696963 93.2854776. 2.68348E -09 6.3082043 6.695224654 xl 1.626361 0.055654057 29.22268801 8.79568E -07 1.4718404 1.780881889 n.tcorsconci4 ccnoanvnntc•rnaer_c VI a nkton ll•�d ou NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK Vault Dead Pool Storage Volume 1 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 0,667 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 79,200 1.818 85 IMPERV AREA (sf) = 339,605 7.796 98 tc (min) = 6.3 INFLOW Qp (cfs) = 0.989 Qp (gpm) = 444 Tp (min) = 7.67 VOLUME (cf) = 13,663 Page of DATE: 08- Jun -98 BY: BEK CHKD BY: JOB # 98020C 1.0000 0.9000 0.8000 v 0.7000 0,6000 a 0.5000 4.3 0.4000 N 0.3000 0.2000 0.1000 0.0000 INFLOW INFLOW O d O S O f co TIME (HOURS) D :ISPREADSHE.EET\98020C1WQ- STM.XLS 8/8/98 I :58 PM NELSON - BOURDAGES e division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 2 2 -YEAR, 24-HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.00 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 187,900 4.314 85 IMPERV AREA (sf) = 2,340 0.054 98 tc (min) = 6.8 I N FLOW Qp (cfs) = 0,791 Qp (gpm) = 355 Tp (min) = 7.67 VOLUME (cf) = 12,789 DATE: 01- Jun -98 BY: BEK CHKD BY: JOB M 98020C 0.8000 0.7000 0.6000 u. v 0.5000 w tgi 0.4000 Q 5 0.3000 N 0 0.2000 0.1000 0.0000 8 0 INFLOW INFLOW 0 S TIME (HOURS) D: \ SPEADSHE. ET\ 98020C\ OUTFALL2 \[2YR- STM.XLWJ2YR- PRE.XLS. NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 2 10 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.90 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 187,900 4.314 85 IMPERV AREA (sf) = 2,340 0.054 98 tc (min) = 6.8 IfirL W Qp (cfs) = 1.656 Qp (gpm) = 743 Tp (min) = 7.67 VOLUME (cf) = 24,069 DATE: 01- Jun -98 BY: BEK CHKD BY: JOB II 98020C 1.8000 1.6000 1.4000 v 1.2000 1.0000 0.8000 0.6000 b 0.4000 0.2000 0.0000 8 INFLOW INFLOW 8 0 8 v ao N TIME (HOURS) D: \SPEAR SHEET-198 020C \OUTFALL2 \(10YR- STM.XLWJ1 OYR -PRE*S NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE- DEVELOPMENT OUTFALL NO. 2 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 187,900 4.314 85 IMPERV AREA (sf) = 2,340 0.054 98 tc (min) = 6.8 Qp (cfs) = 2.859 Qp (gpm) = 1,283 Tp (min) = 7.67 VOLUME (cf) = 39,628 DATE: 01- Jun -98 BY: BEK CHKD BY: JOB N 98020C 3.0000 2.5000 y 2.0000 W ce • 1.5000 1.0000 0.5000 0.0000 INFLOW INFLOW 8 8 TIME (HOURS) D• 1SPFADSHF .FT198 020C10UTFALL21r100Y STM.XLW1100Y- PRE.XLS NELSON - BOURDAGES a division of Poggemeysr Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 3 2 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.00 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,760 2.612 85 IMPERV AREA (sf) = 0 0.000 98 tc (min) = 6.8 INFLOW Qp (cfs) = 0.464 Qp (gpm) = 208 Tp (min) = 7.67 VOLUME (cf) = 7,534 DATE: 26- Apr -98 BY: BEK CHKD BY: JOB H 98020C 0.5000 0.4500 0.4000 LL 0.3500 U 0.3000 — 0.2500 v 0.2000 N 0 0.1500 0.1000 0.0500 0.0000 0 0 0 INFLOW INFLOW 0 0 o 0 v cd cJ v; TIME (HOURS) 0 D:\ SPEADSHE. ET\ 98020C\ OUTFALL3 \(2YR- STM.XLWJ2YR- PREXLS NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 3 10 -YEAR, 24-HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.90 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,760 2.612 85 IMPERV AREA (sf) = 0 0.000 98 tc (min) = 6.8 INFLOW Qp (cfs) = 0.980 Qp (gpm) = 440 Tp (min) = 7.67 VOLUME (cf) = 14,257 DATE: 28-Apr-98 BY: BEK CHKD BY: JOB 0 98020C 1.0000 0.9000 0.8000 uu.. 0.7000 "C" 0.6000 ce • 0.5000 z 0.4000 U D. 0.3000 0.2000 0,1000 0.0000 INFLOW INFLOW O O 0 0 0 0 o v ad (ti TIME (HOURS) o. 0 D:\ SPEADSHE. ET1 98020C\ OUTFALL31 [10YR- STM.XLWJIOYR-PRE.XLS NELSON - BOURDAGES e division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 3 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,760 2.612 85 IMPERV AREA (sf) = 0 0,000 98. tc (min) = 6.8 INFLOW Qp (cfs) = 1.699 Qp (9pm) = 762 Tp (min) = 7.67 VOLUME (cf) = 23,544 DATE: 26-Apr-98 BY: BEK CHKD BY: JOB # 98020C 1.8000 1,6000 rn 1.4000 16 1.2000 I" 1.0000 0.8000 N 0.6000 0.4000 0,2000 INFLOW INFLOW 0.0000 0 0 0 00 00. 00 0 °o • 0 c'i 0 • 0 • TIME (HOURS) D:\ SPEADSHE .ET \98020C \OUTFALL3 \(100Y STM.XL.WJ100Y- PREXLS STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN FIGURE III-1.1 Volume Correction Factor to be Applied to Streambank Erosion Control BMPs Based on Site Impervious Cover SO 43 4o% -0.- 40 35 30 25 20 15 10' 1 1 0 20 40 80 SITE IMPERVIOUS COVER 00 GO 74 c'/0 100 , • ' , , . • • . • • • , • . • • • , • . • . IIIr1-3' . ' FIBkUAY, 1992 OUTFALL NO. 1 - DISCHARGE CALCULATIONS A summary of the 6 -month (1/2 the 2- year), 2 -year, 10 -year, and 100 -year, 24 -hour storms for discharges to Outfall No. 1 follows: Outfall No. 1 Return Period Pre Development Post Development 6 -month 0.43 cfs n/a 2 -year 0.86 0.76 cfs 10 -year 1.57 1.17 100 -year 2.53 1.67 As illustrated in the table, Outfall No. 1 does not meet the 6 -month cutoff during the 2 -year storm event. We feel that this is not an issue as the post - development hydrograph is inside the pre - development hydrograph when flows are above the 6 -month cutoff. Therefore, the duration of the post - development peak flows will be equal to or less than existing conditions and the duration of high discharge will not be increased or sustained for extended periods of time. In addition, the post - development peak flows will always be Tess than the pre - development peaks. We feel that the system does meet the intent of Chapter III of the "Stormwater Management Manual for the Puget Sound Basin ". The proposed total run -off volume is approximately 18% (2,396 cf) less than existing conditions for the two -year storm event. The reduced volume should have minimal impact on downstream water courses. As described in the Downstream Analysis Report, there are no wetlands or habitat areas between Outfall No. 1 of the site and Riverton Creek. Riverton Creek has documented flooding problems and will not be adversely affected by the reduced volume. Spreadsheet output follows. r 1 t' 1 r c c: C d (. ( ( (. Z J -J D 0 to a CD O o =0 wrt 0I J 4 W N o� 2• 0 Q a 11 O O O G 1!! (SAO) 3921VH3SIO OO1 Z oo,OZ 00'9 6 00'8 N U J X a re 9 2 0 cnW u.i a.. 0017 • I 1 1 1 • 1 1 RE -DEVEL OST -DEVE 1 1 1 • • 1 1- 1 it 1 a 1 1 1� 1 1 • a 1 • • 1 • • • • • • • II 1 1 • 1 I 1 1. II. - 1 11 O O O G 1!! (SAO) 3921VH3SIO OO1 Z oo,OZ 00'9 6 00'8 N U J X a re 9 2 0 cnW u.i a.. 0017 c r f C 1 c C C C C C C C. ( Y. C a W ( U L ( O,_ C wz Erf ( U J J ( U aO 1 C c c:. c.. r.. c C C C 1 C 1 C C C7 0 f‘ =0 U) 2O ax 94 W Q W f'- a' 0 2 w a 0 0 to ' 0 0. 00't7Z 00'0Z 00'91. z 00'Z z W 00'9 00't7 00'0 CV r (S43) 3EJZIVH3sIa • PRE- DEVELOPMENT POST- DEVELOPMENT 1 1 • —f- .1 1 i 1 • r r M al . . . • . w is • • 0 • . . . . • • • 1 0 0 to ' 0 0. 00't7Z 00'0Z 00'91. z 00'Z z W 00'9 00't7 00'0 CV r (S43) 3EJZIVH3sIa NELSON - BOURDAGES a division of Poggemeyer Design Group PACIFIC VIEW OFFICE PARK PRE- DEVELOPMENT OUTFALL NO. 1 2 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.00 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,040 2.595 85 IMPERV AREA (sf) = 37,440 0.860 98 tc (min) = 6.8 INFLOW Qp (cfs) = 0.864 Qp (gpm) = 388 Tp (min) = 7.67 VOLUME (cf) = 13,020 DATE: 24- Apr -98 BY: BEK CHKD BY: JOB H 98020C 0.9000 0.8000 N 0.7000 u 0.6000 LU • 0.5000 a 0.4000 s y 0.3000 • 0.2000 0.1000 0.0000 INFLOW INFLOW O 0 0 0 0 0 d v ad cd TIME (HOURS) 0 D:I SPEADSHE. ET1 98020C\ OUTFALL1 1(2YR- STRMXLWJ2YR- PREXLS NELSON - BOURDAGES a division of Poggemeyor Design Group PACIFIC VIEW OFFICE PARK PRE - DEVELOPMENT OUTFALL NO. 1 10 -YEAR, 24 -HOUR STORM INPUT:. TOTAL PRECIPITATION (in) = 2.90 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,040 2.595 85 IMPERV AREA (sf) = 37,440 0.860 98 tc (min) = 6.8 INFLOW Qp (cfs) = 1.571 Qp (gpm) = 705 Tp (min) = 7.67 VOLUME (cf) = 22,490 DATE: 24 -Apr -98 BY: BEK CHKD BY: JOB # 98020C 1.6000 1.4000 N 1.2000 LL 1.0000 w ce 0.8000 4 v 0.6000 co c 0.4000 0.2000 0.0000 INFLOW INFLOW o 00 0 oo 00 0 o vi ad :11 o 0 N TIME (HOURS) OAS PEAOSHE.ET\96020C\OUTFALL1 \(10YR-STM.XLWj10YR- PRE.XLS NELSON - BOURDAGES a division of Pogpemeyer Design Group PACIFIC VIEW OFFICE PARK PRE- DEVELOPMENT OUTFALL NO. 1 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 113,040 2.595 85 IMPERV AREA (sf) = 37,440 0.860 98 tc (min) = 6.8 INFLOW Qp (cfs) = 2.527 Qp (gpm) = 1,134 Tp (min) = 7.67 VOLUME (cf) = 35,232 DATE: 24-Apr -98 BY: BEK CHKD BY: JOB # 98020C n•1CDCeneWR f=' P1osn9nrinl'Trim 1 1trinnv GTAAXI WI1nnY-PRir r r r 1 • 1 NELSON - BOURDAGES a division of Poggameyor Design Group PACIFIC VIEW OFFICE PARK POST - DEVELOPMENT OUTFALL NO. 1 2 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.00 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (sf) = 10,800 0.248 85 IMPERV AREA (sf) = 67,035 1.539 98 tc (min) = 6,8 INFLOW Qp (cfs) = 0.765 Qp (gpm) = 344 Tp (min) = 7.67 VOLUME (cf) = 10,624 DATE: 24 -Apr -98 BEK CHKD BY: JOB # 98020C 0.8000 0.7000 - F 0,6000 w E--). 0.5000 w ° 0,4000 4 X 0.3000 N C 0.2000 0.1000 0.0000 0 O INFLOW INFLOW o o o o o eci ( o TIME (HOURS) 11 n.t ooeeneuc e•1oon9nrstrii ITPAI 111r9VCI.CTR1.A VI VVI9YR.PCICTVI C .' NELSON - BOURDAGES division of Poggerneyer Design Group PACIFIC VIEW OFFICE PARK POST - DEVELOPMENT OUTFALL NO. 1 10 -YEAR, 24-HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 2.90 BASIN: OUTPUT: AREA (sf) AREA (acres) CN. PERV AREA (sf) = 10,800 0.248 85 IMPERV AREA (sf) = 67,035 1.539 98. tc (min) = 6.8 r— INFLOW Qp (cfs) = 1.166 Qp (9pm) = 523 Tp (min) = 7.67 VOLUME (cf) = 16,257 `j DATE: 10-Jun-98 BY: BEK CHKD 8Y: JOB # 98020C 1.2000 1.0000 rn v 0.8000 W 0.6000 N 0.4000 c 0.2000 0.0000 •� 0 INFLOW INFLOW 0 0 S 0 ry TIME (HOURS) D:\ SPEADS HEM' \ 98020C \OUTFALL11[10YR- STM.XLWJ10Y POST.XLS NELSON - BOURDAGES ■ division of Poggenwysr Design Group PACIFIC VIEW OFFICE PARK POSV- nEVELOPMENT OUTFALL NO. 1 100 -YEAR, 24 -HOUR STORM INPUT: TOTAL PRECIPITATION (in) = 4.03 BASIN: OUTPUT: AREA (sf) AREA (acres) CN PERV AREA (st) = 10,800 0.248 85 IMPERV AREA (sf) = 67,035 1.539 98 tc (min) = 6.8 INFLOW Qp (cfs) = 1.673 Qp (gpm) = 751 Tp (min) = 7.67 VOLUME (cf) = 23,428 DATE: 10-Jun-98 BY: BEK CHKD BY: JOB 0 96020C 1.8000 1.6000 — 1.4000 u 1.2000 ILI 1.0000 0.8000 0 0.6000 0.4000 0.2000 0.0000 8. INFLOW INFLOW 0 S S ad TIME (HOURS) D:\SPEADSHE.ET\98Q20C\OUTFALL1 \[100Y STM,XLW)100- POST.XLS BIOSWALE CALCULATIONS NELSON- BOURDAGES Pape or a dMs on of Poppemeyer Deslpn Group DATE: 10-Jun-98 BY: BEK CHKD BY: JOB / 98020C PACIFIC VIEW OFFICE PARK Bioswales 1 OBJECTIVE SIZE BIOSWALES FOR WORST CASE FLOWS (NORTH SWALE) I1 DESIGN CRITERIA 111 METHODOLOGY PEAK INFLOW: OPEN CHANNEL: SIZE FOR 6- MONTH, 24HR STORM AT 4" DEEP SIZE FOR 100 YR, 24HR STORM WITHOUT OVERTOPPING PEAK INFLOW WILL BE CALCULATED USING THE RATIONAL METHOD, WHERE Qr = CIrA Qr = PEAK FLOW (cfs) FOR A GIVEN STORM RETURN PERIOD r C = RUNOFF COEFFICIENT, TABLE 4.3.3A, KC DESIGN MANUAL Ir = PEAK RAINFALL INTENSITY (In/fh) FOR A GIVEN RETURN PERIOD r A = AREA OF DRAINAGE BASIN (acres) Ir = Pr'(ir) Pr = TOTAL PRECIPITATION FOR THE DESIGN STORM OF RETURN PERIOD r. (FROM ISOPLUVIAL MAPS) it = (ar)'(Tc) ^( -br) ar = COEFFICIENT FOR RATIONAL METHOD. (TABLE 4.3.38) br = COEFFICIENT FOR RATIONAL METHOD, (TABLE 4.3.38) Tc = TIME OF CONCENTRATION (min) Tc = L/60V WHERE, L = FLOW DISTANCE (ft) V = AVERAVE VELOCITY ACROSS LAND COVER (fps) = Kr(So)^0.5 Kr = Tc VELOCITY FACTOR (fps), FIGURE 4.3.38, KC DESIGN MANUAL So = AVERAGE LAND SLOPE (ft/ft) OPEN CHANNELS WILL BE SIZED USING MANNIGS EQUATION; Q = (1.49 /n) "AR ^2/3So ^0.5 WHERE, Q = FLOW IN CHANNEL (cfs) n = MANNINGS ROUGHNESS COEFFICIENT A = AREA OF FLOW IN CHANNEL (sf) R = HYDRAULIC RADIUS (ft) So = CHANNEL SLOPE (ft/ft) VELOCITIES IN THE CHANNEL WILL BE ESTIMATED WITH DARCY'S LAW; V (fps) = QIA LINER STRESS IS ESTIMATED AS; T = 62.4YSo WHERE, T = SHEAR STRESS (psf) Y = DEPTH OF FLOW IN CHANNEL (ft) So = CHANNEL SLOPE (ftft) D:\SPREADSHEETr98020CW BIOSWL.XLS IV CALCULATIONS 6- MONTH, 24 -HOUR PEAK INFLOW: AREA (acres) = 2.36 C = 0.90 <==TABLE 4.3.3A, KC DESIGN MANUAL L (ft) = 745 So (ft/ft) = 0.02 K2 = 20 < == FIGURE 4.3.3C, KC DESIGN MANUAL P2 (in) = 2 <= =FROM ISOPLUVIAL MAPS a2 = 1.58 <= =TABLE 4.3.3B, KC DESIGN MANUAL b2 = 0.58 <= =TABLE 4.3.38, KC DESIGN MANUAL Tc (min)= 6.3 12 (in/hr) = 1.09 Q2 (cfs) = 2.30 Q6m (cfs) = OPEN CHANNEL: Q(cfs) = 1.2 S (ft/ft) = 0.02 n = 0.07 B(ft) = 3 M= 3 CHANNEL VELOCITY V(ft/s) = Q/A LINER SHEAR STRESS T(Iblft ^2) 11.15 J AR ^2/3 = nQ/1.495^2 nQ/1.49s ^2 = < == GRASS f(M,y,B) = ARA2/3 = y(ft) NORMAL DEPTH • 0.38 0.40 IIIIMra:- 1.07 0.35 100-YEAR 24 -HOUR PEAK INFLOW: AREA (acres) = 2.356 C = 0.9 L (ft) = 745 So (ft/ft) = 0.02 K100 = 20 P100 (in) = 4.03 a100 = 2.61 b100 =0.63 Tc (min)= 6.8 1100 (in/hr) = 3.14 Q100 (cfs) = OPEN CHANNEL: LINING: CONCRETE Q(cfs) = 6.67 S (ft/ft) = 0.02 n = 0.07 B(ft) = 3 M =3 CHANNEL VELOCITY V(ft/s) = LINER SHEAR STRESS T(Ib/ft ^2) _ 6.67 1.83 1 1111.1111 :U1111111 <= =GRASS <= =TABLE 4.3.3A, KC DESIGN MANUAL < == FIGURE 4.3.3C, KC DESIGN MANUAL <= =FROM ISOPLUVIAL MAPS <= =TABLE 4.3.3B, KC DESIGN MANUAL <= =TABLE 4.3.38, KC DESIGN MANUAL ARA2/3 = nQ /1.49s ^2 nQ/1.49s ^2 = f(M,y,B) = ARA2/3 = Aft) = 2.21 2.25 0.71 D:1 SPREADSHEEn98020C1N_BIOSWL.XLS WEIR AND SPILLWAY CALCULATIONS. t 1 r: C 1 1 C C C 1 C C C C C C Et: NELSON - BOURDAGES, INC., P.S.. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Male by r6e� Date q5115 Job No, 98aZOc Checked by Date Sheet No, Description S}`012-1AW ATVC C A-Ac.) LA-Tit/1'6 Job Name \ CR- CA VAA- A--TN®YS St Zs THE vJ Vci .0, A( ■APPOIAt. FtM1VY2. Se∎Lt.WA t' LA) Et , F•'-A■ \NA- 01\\.b, ski:'\ l.l.v!(l�t .CQ 'A IS MA Mvi.A 00 i .,r) -0W Fre,zt!\ srevs" (o -ro e01. -,h ()k. v i 11 Q^\1. k `(ZS. v , eor S-4vt"w, '(= (--o\J �0 'b t'vt✓"Nal ; -N �/�v ��T• TvJO ` S1 r vJ vU ILL (3 t; U i:'t-) • �v *-n! Pri .. Y2 r t . /1 1 tM t T 1-i t FIST W w2- .,tl 1 t1.: `°R S s Tki.E Z ke eWZ• sTu R 1-A' c'L Ow A m f ri S EZ._dwr) STf' C . ■.•0 t t-L- 06(.6 '_(•,1-i l p 0 yetye. 'Ft J 1 r 1 i L 1. r. r_ C r_. L C L l� C C NELSON- BOURDAGES, INC., P.S. , Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425)827-5995 • FAX (425) 828.4850 Made by �V�L Dated /. f a Job No, �� Zoe Checked by - Date �� Sheet No. Description Job Name RIN C .A \C. i LA-T1 VANS �rz o L. Q ■1.,65 0,93. Cw VI 'r 3.0 CO, SI/L- z s 03; p-_ 3.o CZ o> ILAb5C.cS 0.35 (Zt ) Sso 1E \1 'X91i vN��s Cv■+S±ntc.%I wA \\ 3 1361 CO WO f STRUCTURAL CALCULATIONS SHORING & RETAINING WALLS For: PACIFIC VIEW OFFICE PARK Tukwila, WA June 10, 1998 NB JOB 98019 L EXPIRES OCTOBER 24 Virw.ssi µ PR6- orn MI'IB 013,1 RECEIVED JUL 1 61598 RECEIVED CITY OF TUKWILA JUN 1 51999 PERMIT CENTER. NELSON- BOURDAGES. a Division of Poggemeycr Design Group, :Inc. 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827-5995 • Fax (425) 828 -4850 �•. NELSON - BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made'by GGl. .ate ' l`�� Job No, a /�� C ecked by Date S eet No. ' Description �w P f3.. -, t-- 1470,1-64-- - •:1-ea -Ih/Gr 7 Job Name P ,At-if lG VIVA) _ H 1'31' 12,671. CANTILEVER -TYPE SOLDIER PILE PENETRATING SANDY SOIL NELSON - BOURDAGES Date: 5/28/98 I Job No.: 98019 Job Name: Pacifice View, Building A I Location: Section 1 GS INPUT EXy Za Zb Height of Retained Soil, H = Spacing Left of Pile = Spacing Right of Pile = Pile Diameter = 14.00 ft 8.00 ft 8.00 ft 2.50 ft Influence Factor on Pile Diameter = Active Soil Pressure = Passive Soil Pressure = Depth Increase Factor = 2 40.0 pcf 300.0 pcf 1.2 OUTPUT F1 = 31.36 kips F2 = 8.50 kips F3 = 115.24 kips F4 = 10.25 kips F5 = 85.83 kips X= Y= Za = Zb = D= MINUMUM DEPTH OF PILE : TOTAL LENGTH OF PILE xi MAXIMUM MOMENT ON PILE = Pile Fy = 3.80 if 13.98 ft 1.24 ft 3.59 ft 22.61 ft 27 ft 41 ft 505.39 K -ft © 26.02 ft from T.O.P. 50.00 Ksi Use: W24x84 Mr = 539.0 K -ft I = 2370 in4 Est. Deflection Due to Pile Flexure - 0.11 in NELSON- BOURDAGES; INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by L C� ' .ate Jo• No. let, (q // Checked by (Date Sheet No. 3 Description t, ,r.� A,/J, Ile Job Name fikill fiL v ..5POP I NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by Le"...- uate 64 /q"), l Job No. Iciftv6 Checked by Date Sheet No. 4. ( Description p1 AN� l� i1 W 1, - job Name igG U11sw 4 l At G'6t6(4 NELSON- BOURDAGE, INC., P.S. Consulting Engineers 512 Sixth Street South Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828 -4850 Made by LGe..- 1. etc 4 elf') ( //'° Job No. *D) Checked by Date Sheet No. Description 43 u-itA t w i ,( Job Name fl L vA au 444 re l N6r e - FOOTING AT GRID "A" NELSON- BOUR• DAGE$, INC., P.S.. Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by LGL i, ate.i-M, ! Job No. 1) L. 1 G� I Consulting Checked by Date Sheet No. / Description h pc Job Name (7A.L1 ept 6 \A " ..-> 1 PE-ckt GP' W Se-u. Sa-e -o ii"(. , 40 (?t k -fie 2r r -30-t 1204446(AAt 004 15/444:A5N I ,I II I I =I I I 1 X41 III I 3 La it 44" Not 7 („ ,; @'; 7 (v5- alock Nor - 4t16 p rs :. NELSON- BOURDAGE\S, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.(5995 • FAX ( 828.4850 Made by t.Gty� Job No. p„ I V v Checked by ratejAvait ate Sheet No, Description ij �n, , _ �t �{(s(/�+� (44,2.5.) Job Name (.� pt VI 5W C9, CL� (bo1# RUssi 1,6r= - 1 64 A-E,TA:Ae. Ple-roA '• ett Ftgs cwrT. kizzrk 1'1 ,� 1i 1 , I , t T /.' 2(�L eeL • P-1444, th2beomee 476.0 e-s-r- NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by L� Date 4-- /fig . ! ,, Job No. i L� CV* / / Checked by Date Sheet No. 3 Description $ x^, /mo1 Job Name r*.LI ric vti,w. 64/-4A? t ' t'/4I o, l t/ } ,,ref /•L,? • 4ge1713 +0,obo K271, 1 -7,01 tioN o✓4 t. / r =-0. D-07- X IyX D; ti 18 . .'' 414. i Gb NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Ma4e •y Lc.� Dater -1 / n Job No. c2CPO/� Checked by Date Sheet No. 4. Description P �'�. � & p Job Name piston,, L vg ` ‘142412 A •Ctrw.verovw Wfr t.- ' ZsL z 43T) , ( 9 e41 63.1„ 'rod (e to-r4) CA\Atet4A-W 614A ∎ } = � ( ' )C l i g (J'. 33 1-07,>1-9 Fot.9461-* '!X 1 ),c�,.�� l, K 745-7 -6170 ro 16 — ��%?'� �xv 4/4 t Pti, 2-41-7 33,r) , 11 r + + 14,422, 4A7A+ NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 20 c rkland, WA 98033 (425) 827.5995 • FAX ( ) 828.4850 uj 660 Checked by Description date —P.eq? Sheet No. k ob Name =_. /49_32_1_ -_-_ 3s-D J-trtip rsF, ex. � Feinttlef PD-ec. 1,601s—)1 vats. ss 0.1-f 64-v4 .4`1 )4.4d- At. : zq.`levi= 176 0-2- Vv = —o, ('S ,o,z- )% ,a-o ±`94 3.26 ?Pu R oc 40 F41 e44 IAA tt- l, x a3 440 441, (11: MA W7.11)( 6°X-I tvvy,0 T) n Ar7 AC; Yeti ∎•••••••, «..w«. ..•.110,40*..,.«411w0.w4+.. ....+.. NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by / `� !' Date ,�/3�9, Job No.1/ Checked by Date Sheet No, Description P ` (jam Job Name �,,/,r�G tl +d w, /t tb�•1�. ..�� /^ tsfl twV ,t �x (ctk) vy-fryti, x ys. Ole 1.17,1 t5 t%vA'- INvr (.2) 7. --. NELSON- BOURDACES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Ma_e •y L Date �� �6 Job No. /__ /tT' Checked by Date Sheet No. 1•w Description P UP r A Job Name r (1. 1c , , I 4 f , /x PAidckfzilt. FIN1 -pm-0'11\24, 170-et. r'-1444- ot3 /IA NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (44225)) 828 -4850 Made by �� Date eiv J � Q Job No, q�iq / Checked by Date Sheet No. Description i i iv6ctig Job Name p .p, 1, `' 1 I Dw _ L A tl 1' is t 146 le .= s 6/4. atv‘tZ4-44 >eA) -416er —4+ 6t _ 1./4),v D,odireuric (2" - LAA d mss' vc =6•tittYk)eii; OP) 44 3"" FOOTING AT GRID. 12 NELSON- BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827.5995 • FAX (425) 828.4850 Made by 4.. 6.6,, Date 4-/yi /Q /�, 7d' Job No. . Q Cn � Checked by Date Sheet No. , .-t., Description ftn- , M kA Job Name pAcAfies. V ( `2 F94/ kax . ( )nrt./ . �/ / /03'ao' _i Lou 5.01 L L S�. x47 G st Or' 613 ( %P gin 3,6r -Lr n s'ur'f NELSON - BOURDAGES, INC., P.S. Consulting Engineers 512 Sixth Street South, Suite 202 • Kirkland, WA 98033 (425) 827 -5995 • FAX (425) 828.4850 Made .y Lei Date Job No, Q u (q /a Checked by - Date Sheet No. 11 Description � ' i• r - Pc Pr!:tii�v�7vv�I Job Name (7 -f� G .V / r„ 0„t143 v 4 -x Grp bah )61 -r) d.4. v. -x-44. x,41._ = way, ic.,4714. July 15, 1998 (1 City of Tukwila Department of Community Development Dave. Swanson, P.E. Reid Middleton 728 - 134th Street SW, Suite 200 Everett, WA 98204 RE: Structural Review Pacific View Office Park - Keystone Walls (MI98 -0130) Pacific View Office Park - Retaining Walls (MI98 -0131) Pacific View Office Park - Shoring Walls (MI98 -0132) . Dear Mr. Swanson: John W. Rants, Mayor Steve Lancaster, Director Please review the enclosed plans and documents for structural compliance with the 1994 Uniform Building Code. If you should have any questions, please feel free to contact me at 206- 431 - 3671. Sincerely, 4 U Brenda Holt Permit Technician encl xc: MI98 -0130 WtY(!98-01;31 MI98 -0132 6300 Southcenter Boulevard, Suite #100 Tukwila, Washington 98188 • 20):'00070::: • Fur (20t 05/07/98 TEUJ 15:58 FAX 206 281 0920 Saber Construction Corp 'REGISTERED AS PROVIDED BY LAW AS CONST TCONT GE NERAL W i UgREOI.TRAt ON t • aCk— " ' 4 ' :.10%A8%1985;'•. 1�SUt:uu:. }d;a..rttar,t:a • ••il!!'. •SY7A .•'.t.. ^.tliii:: .v, . ai'.t::uiii %�:.t.iiHiUj 'SABEY ,CORPORATION . 101 ELLIOTT W STE 330 • SEATTLE WA 98119 11625.052.000 c8/991 Demch And Display Certificate • State of Washington County of Mill I certify that this is a true and correct copy of,a possession ofroL as of this date. Dated:5lif Swm ,G>-L o Lamp CONNIE J. TAYLOR STATE OF WASHINGTON NOTARY PUBLIC MY COMMISSION W1 $ 44r01 Ot Title My appointment expit¢as '