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HomeMy WebLinkAboutSEPA EPIC-149-80 - MCCALLISTER WILLIAM - 58 UNIT CONDOMINIUMPARK TERRACE CONDOMINIUMS MCALLISTER CONDOS S 153 STREET EPIG149 -80 w " City of Tukw. 6200 Southcenter Boulevard PLANNING DEPARTMENT Tukwila Washington 98188 • TRANSMITTAL 1908 DATE OF TRANSMITTAL 3 / NOV / $ O TO: U BUILDING DEPT. ❑POLICE DEPT. ❑ FIRE DEPT. ❑ RECREATION DEPT. ❑ PUBLIC WORKS DEPT. ❑ PROJECT: /1144.1.1.1 ST% - GO 4 O S LOCATION: ESiIZT ISRIA.1140S — S. 153 ("A ST. The above mentioned applicant has submitted the following plans or materials for the above reference project: C.Kvironmental Checklist ❑ Preliminary Plat ❑Environmental Impact State- ❑Final Plat ment [t Site /Development Plans ❑ Rezone Request ❑Shoreline Permit Application[] Variance Request ❑Conditional Use Permit ❑Other: Application The attached materials are sent to you for your review and comment. The Planning Dept. needs your comments to satisfy review procedures and to complete the project file. Please use the space provided below for your comments or attach a separate sheet. Requested response date: 10 / 140V/ top Review Department comments: -TA C s c /o, / i, S 6 Cf nr/t/0 DOES Ivor D REG ' 7L CO, v0 /7/O./VS 01= R,4Rk rtiC S T At GS ,¢ c Tu,¢ z- T -/S S,T L u✓¢`1 8.E 0/V SZ-VbRE SLoP4c,c Th<�47 �/o /1T /v1.�4 E T'/ - t C ti 17 T 1/ r' O AL S 1 �- L L ,S' / c ti o L-S' / /? /l ff z�RDoo S S lfit-T SE-vbJ?L SLOff-S 1 3 Z - - LA/vD SC,¢ ,ItiP R,4-R K" - 8 E Cc I= /ti2:„61 70 - TIveG y (JEL mil Z7Ats By: ,t,e Date: 7 / / J' 4P City of Tukwili 6200 Southcenter Boulevard PLANNING DEPARTMENT Tukwila Washington 98188 TRANSMITTAL DATE OF TRANSMITTAL 3 / NOV ! $ O TO: ❑ BUILDING DEPT. ❑ POLICE DEPT. FIRE DEPT. ❑ RECREATION DEPT. ❑ PUBLIC WORKS DEPT. ❑ PROJECT: MG6.L.L151 -X1 c.ONDOS LOCATION: ES1t1' 'VRM% 11Q S • 5 . 153 a ST The above mentioned applicant has submitted the following plans or materials for the above reference project: Environmental Checklist ❑Preliminary Plat ❑ Environmental Impact State- ❑Final Plat ment Site /Development Plans ❑Rezone Request ['Shoreline Permit Application❑ Variance Request ['Conditional Use Permit ❑ Other: Application The attached materials are sent to you for your review and comment. The Planning Dept. needs your comments to satisfy review procedures and to complete the project file. Please use the space provided below for your comments or attach a separate sheet. Requested response date: 10 / NOV/ 250 Review Department comments: Due to the nature of the ground the buildings are to be built on and the excess problems) These buildings would be required to be sprinklered. In addition, the amount of water necessary to protect these buildings may be in adequate due to the configuration of the water system in that area. Date: November 5, 1980 PLANNING DEPARTMENT TRA,NSM ITTAL DATE OF TRANSMITTAL 3 / F400/ 80 TO: ❑ BUILDING DEPT. ❑ POLICE DEPT. ❑ FIRE DEPT. ❑ RECREATION DEPT. PUBLIC WORKS DEPT. ❑ PROJECT: P■GD.l,l,l$Teit CONDOS' LOCATION: ES1t (• 1UPoN0S – S• 1531± sT . The above mentioned applicant has submitted the following plans or materials 'for the above reference project: Environmental Checklist ❑ Preliminary Plat ❑Environmental Impact State- ❑Final Plat ment g-te /Development Plans ❑Rezone Request ['Shoreline Permit Application❑ Variance Request ['Conditional Use Permit ❑Other: Application The attached materials are sent to you for your review and comment. The Planning Dept. needs your comments to satisfy review procedures and to complete the project file. Please use the space provided below for your comments or attach a separate sheet. Requested response date: 10 / NOV / 60 Review Department comments: i s F ,v.._ sc:12 _ 't w ID PvIND (6\ r lv i unto fp .. 0 c „Q Wit 'xl-t --ri c cTu lo \I [Le-04k iLAfn "-u Fib r ', s g 0 v \� S 1 4± sr rzirsfn-i-\I Ivec,caS 1 If AcLp.3 1t7 V`n \INk S\ P1611( O\ T PUri►r Uf'�u�y.,_„ P.s\ Li) F R stiNNE s cc_u o rN No el- CCU IS °/7 P\Dt MT, N/f- y� ov i � v ( L . �'f \1 IU,.Y t_ l A � f - = t ft_' "Mud C,IC,S -� E ' iM, 1 `E� " O I ls S CL •'ot6 jc,. p -¶ tS 1 4SASPAUL— 01 By:-3 Date: ��1�1� 0 R Di � P VYI V\11 c?' L.. fA l \MN. '1't old 1 (�1 NIA) City of Tukw 6200 Southcenter Boulevard Tukwila Washington 98188 PLANNING DEPARTMENT TRANSMITTAL -- DATE OF TRANSMITTAL 3 / NOV / 2.o TO: ❑ BUILDING DEPT. ❑ FIRE DEPT. ❑ PUBLIC WORKS DEPT. • ❑ POLICE DEPT. CREATION DEPT. PROJECT: , NIGAl.A.1S LQ C.04 POS es -;T ItiettINUS - S. 153x= ST. LOCATION: The above mentioned applicant has submitted the following plans or materials for the above ref rence project: Environmental Checklist ❑Preliminary Plat ['Environmental Impact State- ❑Final Plat ment Ei'Site /Development Plans ❑Rezone Request ❑ Shoreline Permit Application❑ Variance Request OConditional Use Permit ❑Other: Application The attached materials are sent to you for your review and comment. The Planning Dept. needs your comments to satisfy review procedures and to complete the project file. Please use the space provided below for your comments or attach a separate sheet. Requested response date: 10 / %40) / 80 Review Department comments: 77,E ,.e4,w. ,,,� -�,r k. 4n -4,;2_ A el-P42 G it y' V-e.G ✓��Y /i Osa�/ GGJ� fre. f ilw/i / �tl•/C� a ° Q4,- . sue, is y� Yk,„ !ssHi�eY_1 /T�+r�i.ii t tit %.I %� /f/� T� h ��N6 !�t°S• s+�J LOO..�Cy cL-� ✓//�� T�Y2i1�o/L.� /'lam. I GC 2-ux>- ,044. L By: �o,-�. i'v�� Date: /1 — S =fd • CITY °OF TUKWILA ENVIRONMENTAL CHECKLIST FORM This questionnaire must be completed and submitted with the application for permit. This questionnaire must be completed by all persons applying for a permit from the City of Tukwila, unless it is determined by the Responsible Official that the permit is exempt or unless the applicant and Responsible Official previously agree an Environmental Impact Statement needs to be completed. A fee of $50.00 must accompany the filling of the Environmental Questionnaire to cover costs of the threshold determination.- I. BACKGROUND 1. Name of Proponent: William McAllister 2: Address and Phone Number of Proponent: 3724 Cascadia So., Seattle, Ala. 98144 725 -1980 3. Date Checklist Submitted: October 31, 1980 4. Agency Requiring Checklist: City of Tukwila Building Department 5. Name of Proposal, if applicable: 58 Unit Condominium 6. Nature and Brief Description of the Proposal (including but not limited to its size, general design elements, and other factors that will give an accurate understanding of its scope and nature): 58 unit condominium development with necessary roads, parking and utilities to serve the project. The proposal includes all land - sc� •' • • • - .... • he •ro•osed site plan, and all commitments set out in the appli- cation for waiver, as well as all governmental licenses required for the construction and occupation of the units, including but not limited to approval under the State Horizontal Regimes Act RCU 64.32 7. Location of Proposal (describe the physical setting of the proposal, as well as the extent of the land area affected by any environmental im- pacts, including . any other information needed to give an accurate under- standing of the environmental setting of the proposal): The site for the proposed project is located on the southeast corner of Tukwila Hill. The property size is 4,.'68acres, and slopes to the southeast. 8. Estimated Date for Completion of the Proposal: December, 19S1 9. List of all Permits, Licenses or Government Approvals Required for the Proposal (federal, state and local): (a) Rezone, conditional use, shoreline permit, etc. YES NO (b) King County Hydraulics Permit YES x NO (c) Building permit YES x NO. (d) Puget Sound Air Pollution Control Permit YES NO (e) Sewer hook up permit YES X NO (f) Sign permit YES NO (g) Water hook up permit YES x NO (h) Storm water system permit YES x NO (i) Curb cut permit YES NO (j) Electrical permit (State of Washington) YES X NO (k) Plumbing permit (King County) YES XNO (1) Other: Condo declaration under State Horizontal Regimes Act RCU 64.32 10. Do you have any plans for future additions, expansion, or futher activity related to or connected with this proposal? If yes, explain: No such plans are proposed 11. Do you know of any plans by others which may affect the property covered by . your proposal? If yes, explain: No 12. Attach any other application form that has been completed regarding the pro- posal; if none has been completed, but is expected to be filed at some future date, describe the nature.of such application form: Waiver application.submitted to City II. ENVIRONMENTAL IMPACTS (Explanations of all "yes" and "maybe" answers are required 1. Earth. Will the proposal result in: (a) Unstable earth conditions or in changes in geologic substructures? (b) Disruptions, displacements, compaction or overcover- ing of the soil? (c) Change in topography or ground surface relief fea- tures? (d) The destruction, covering or modification of any unique geologic or physical features ?. YES MAYBE. NO X X X • • YES MAYBE NO (e) Any increase in wind or water erosion of soils, either on or off the site? X (f) Changes in deposition or erosion of beach sands, or changes in siltation, deposition or erosion which may modify the channel of a river or stream or the bed of the ocean or any bay, inlet or lake? Explanation: See attached 2. Air. Will the proposal result in: (a) Air emissions or deterioration of ambient air quality? (b) The creation of objectionable odors? X (c) Alteration of air movement, moisture or temperature, or any change in climate, either locally or regionally? _ X Explanation: A temporary change in ambient air quality due to the construction process can be expected. However, this is expected to minimum because the site is well ,:exposed and subject to good air flow. 3. Water. Will the proposal result in: (a) Changes in currents, or the course or direction of water movements, in either marine or fresh waters? (b.) Changes in absorption rates, drainage patterns, or the rate and amount of surface water runoff? (c) Alterations to the course or flow of flood waters? x (d) Change in the amount of surface water in any water body? x (e) Discharge into surface waters, or in any alteration of surface water quality, including but not limited to temperature, dissolved oxygen or turbidity? x (f) Alteration of the direction or rate of flow of ground waters? _ x (g) Change in the quantity of ground waters, either through direct additions or withdrawals, or through interception of an aquifer by cuts or excavations? --- -3- • • (h) Deterioration in ground water quality, either through direct injection, or through the seepage of leachate, phosphates, detergents, waterborne virus or bacteria, or other substances into the ground waters? (i) Reduction in the amount of water otherwise avail - able for public water supplies? Explanation: •See attached YES MAYBE NO 4. Flora. Will the proposal result in: (a) Change in the diversity of species, or numbers of any species of flora (including trees, shrubs, grass, crops, microflora and aquatic plants)? X _ (b) Reduction of the numbers of any unique, rare or endangered species of flora? X (c) Introduction of new species of flora into an area, or in a barrier to the normal replenishment of existing species? X (d) Reduction in acreage of any agricultural crop? X Explanation: See attached 5. Fauna. Will the proposal result in: (a) Changes in the diversity of species, or numbers of any species of fauna (birds, land animals including reptiles, fish and shellfish, benthic organisms, insects or microfauna)? X _ (b) Reduction of the numbers of any unique, rare or endangered species of fauna? X (c) Introduction of new species of fauna into an area, or result in a barrier to the migration or movement of fauna? (d) Deterioration to existing fish or wildlife habitat? X Explanation: Some small land animals may be displaced. Domestic pets will probably be introduced. -4- X YES MAYBE NO 6. Noise. Will the proposal increase existing noise levels? Explanation: 7. Light and Glare. Will the proposal produce new light or glare? X Explanation: The proposed project will produce new light due to parking and street lighting required for safety, incidental lighting from within the buildings, and from lighting used to accent landscaped areas. 8. Land Use. Will the proposal result in the altera- tion of the present or planned land use of an area? Explanation: See attached. 9. Natural Resources. Will the proposal result in: (a) Increase in the rate of use of any natural resources? (b) Depletion of any nonrenewable natural resource? Explanation: 10. Risk of Upset. Does the proposal involve a risk of an explosion or the release of hazardous substances (including, but not limited to, oil, pesticides, chemicals or radi- ation) in the event of an accident or upset conditions? X X Explanation: Possible during construction, but expected to be minimal, due to compliance with applicable regulations. • 11. Population. Will the proposal alter the location, distribution, density, or, growth rate of the human population of an area? Explanation: The proposal will add 58 families to the area. YES MAYBE NO X 12. Housing. Will the proposal affect existing housing, or create a demand for additional housing? X Explanation: The proposal will add 58 housing units to the area. 13. Transportation /Circulation. Will the proposal result in: (a) Generation of additional vehicular movement? (b) Effects on existing parking facilities, or demand for new parking? (c) Impact upon existing transportation systems? (d) Alterations to present patterns of circulation or movement of people and /or goods? (e) Alterations to waterborne, rail or air traffic? (f) Increase in traffic hazards to motor vehicles, bicyclists or pedestrians? Explanation: 14. Public Services. Will the proposal have an effect upon, or result in a need for new or altered governmental services in any of the following areas: (a) Fire protection? (b) Police protection? (c) Schools? (d) Parks or other recreational facilities? (e) Maintenance of public facilities, including roads? X X X X X X -6- X • (f) Other governmental services? Explanation: 'YES MAYBE NO _X_ The project will place an increased Toad on the services listed above; howeNier, the increase is within the capabilities of the existing facilities. 15. Energy. Will the proposal result in: (a) Use of substantial amounts of fuel or energy? X (b) Demand upon existing sources of energy, or require the development of new sources of energy? --X- Explanation: 16. Utilities. Will the proposal result.in a need for new systems, or alterations to the following utilities: (a) Power or natural gas? (b) Communications systems? (c) Water? (d) Sewer or septic tanks? (e) Storm water drainage? (f) Solid waste' and disposal? Explanation: 17. Human Health. Will the proposal result in the crea- tion of any health hazard or potential health hazard (excluding mental health)? Explanation: X • • 18. Aesthetics. Will the proposal result in the obstruc- tion of any scenic vista or view open to the public, or will the proposal result in the creation of an aesthetically of- fensive site open to public view? Explanation: 19. Recreation. Will the proposal result in an impact upon the quality or quantity of exist- ing recreational opportunities? Explanation: 20. Archeological /Histroical. Will the proposal result in an alteration of a signifi- cant archeological or his - torical site, structure, object or building? Explanation: CERTIFICATION BY APPLICANT: YES MAYBE NO I, the undersigned, state that to the best of my knowledge the above information is true and complete. It is understood that the lead agency may withdraw any declaration of non - significance that it might issue in reliance upon this checklist should there be any willful misrepresentation or willful lack of full disclosure on my part. • KS:i:g ture and Title ea /0 /,90 Date Environktental Checklist For. Attachment II ENVIRONMENTAL IMPACTS • I .(a) Soils analysis indicates that no unstable earth conditions will result from the proposed project. Slope stability will be studied closely throughout design and construction. A copy of the soils analysis is attached . All recommendations in that report are to be done as part of the total proposal. I (b) Disruption, displacement will be areas of cut associated with the roadway at the south end of the property. Elevation changes will be handled with near vertical rockeries, rather than 2:1 cut of fill slopes, thus reducing required grading. All grading and compaction will comply with City speci- fications, and the recommendations of a detailed soils report. I (c) The present contours of the site will be altered only in the areas of construction, and will be done to the minimum extent possible. Existing contours will be maintained between the buildings and in the areas below the buildings. I (e) Grading may result in potential increase of erosion of the soil . In those areas where erosion is possible, erosion protection devices will be employed so that erosion will not be significant. Sedi- mentary control devices will be used where necessary to protect the quality of water runoff during ,construction. All areas subject to erosion will be planted with appropriate material. 3 (b) The rate of surface runoff of storm water will be increased, and existing aborption rates affected, due to the increase in impervious surfaces on the site. Storm water on the site will be collected and routed to present storm drainage systems in a manner to minimize the potential for erosion and ponding of surface waters. Applicant will comply with City of Tukwila storm drainage ordinances in order to minimize the impact of the increase of storm water runoff. 3 (f) Due to impervious surface increase, there might be a slight change. 3 (h) There might be a slight affect due to the uses of fertilizers. See attached geological report for imformation on ground water. 4 (a) The existing vegetation will be removed only in the areas of construction which will result in a (c) Toss of wildlife habitat and temporary exposure to erosion during construction. As a mitigating effort, upon completion the site will be landscaped with plant material that will stabilize the surface soils and provide some habitat for more desirable species of wildlife. During construction, catchment areas to impound potential silt -laden surface runoff will be constructed and maintained. Vegetation buffers will be provided to the greatest extent possible at the site boundaries. 8. Land Use - explanation: The proposal will alter the land use from vacant land to multi - family residential, and is compatible with many of the goals and objectives of the Tukwila comprehensive plan. The property is bordered by other multi - family residential properties and Tukwila Park, which serve as a transition to the single family developments. The project is designed to take advantage of the steep slopes and will maintain a landscape buffer between the units and Southcenter Blvd. Enviroypmental Checklist Fo41) Attachment - page 2 • 13 (a) Assuming 5.6 vehicle trips per unit per day, there will be 325 vehicle trips per day generated on to South 153rd by the project. The peak rate generated is estimated at .4 trips /unit, or 24 vehicles. 13 (b) There will be a demand for new parking based on additional vehicle movement generated by the living units. The on -site parking provided will be equal to that required by Tukwila zoning code.. 13 (c) There will be a minor impact on the existing transportation system, primarily the adjacent road systems, due to the increased traffic from the project. 13 (f) There will be a slight increase in traffic hazards due to the increase of pedestrians, possible bicycle .traffic, and increased vehicular traffic. No+10 111 il I t a 1111 i 1 - 1 • 1 1 1 r 1 poi rpo iiii, 1 tip; Eit �. ;14W it WOW I • ii • • IiI .1111111/p - ` isi i.t=iest Paz,? lik li 1R ipt ill %I f t- ON I 3 J. i i 11 II oil 115 110 1 ti Z HP; i t- , 11 �� _ li 111 i d it F 0 -111ittlisT lAiig;ii i.T ii 1; i 1 b I t i i if -1 : : if i i ! I 1 i ; X 15 y r - -- V* II a . itUtill IP tit%fts1 AAA 111 i °, 1 f r 6 Z + r .J = A coif 4«eet PARK TERRACE CONDOMINIUMS TUKWILLA,WASH. .o.._.a °"" ""° • 6' •• ,.om ° n Z,, `�7 �� nw- �.�.,. �. • �4 STAPP. w4 ' . _ ..._......:..:• .7.r.-7... ...d WY1aIp MIf. WAS V. �Q _ . .-..":.. • •• • . : .••• •.• ••• -•••:••-ti:;"•••" . • • r • . • • A • , • 1 , - • • • [- 6 166. At. •1 1 . ••• • : .'; • ' . Y: i 611 A .9111 T h) I I e ftie4j . . PARK 'TERRACE CONDOMINIUMS TUKWILLA, WASH. IIIMIS 1 a Nr..Twar ar, .... tete. 6.•■••••Ar IA ' ..,4--- ......... MI MIN C.- 11-•• 1 V .. WP • STAPPER WY • i'l • ■ 8 0 A > W exrcWOp- Aiio PARK TERRACE CONDOMINIUMS TUKWILLA, WASH. o... "^°° ° �-� °°`' (� -� ,t - a •, �M aacwre'n'il STAPPEri V1/YATT a�: �,"1 "" p` n /-44.' PT.' A ..o. bravr • ur+rtm c +n - exre ems. PARK TERRACE o n +-+.. n� STAPPER . CONDOMINIUMS �-^M�a ® .WXAT.T TUKWILLA,WASH. °`°� 'ft ...i1,‘ lk • MASTER LAND DEVELOPMENT APPLICATION FORM SUPPLEMENTARY QUESTIOUAIRE Schedule A WAIVER. APPLICATION 1. State specifically the action in Ordinance No. 1137 to Which you are requesting-a waiver: Revise the land use ma designations for show hi h densit residential, so as to permit submitted herewith. 2. Briefly and generally describe the project you are proposing: SEE ATTACHED 3. Is your project unique in terns of design, land use or benefit to the Tukwila community? SEE ATTACHED 4. Is your project' significant in scale? NO • S. If the request for waiver involves building, grading, tion, or filling in an environmentally - sensitive area, solutions do you propose to offset the impact of such clearing, excava- what mitigating activities? ' SEE ATTACHED 6. That goals and policies can you identify which suppoit your request for waiver, if any? SEE ATTACHED 7. In your opinion, do the requirements. of waiver ordinance 1137 impose a hardship on the use and development of this site? SEE ATTACHED: Waiver Application Attachment • • 2. The proposed project is to construct 58 two bedroom townhouse condominium units, together with 58 covered parking stalls, 58 open parking stalls, and all associated roadways, utilities, sidewalks, paths, passive recreation areas and landscaping. The project consists of 7 separate buildings with a total area of 70,300 sq.ft. and a lot coverage of 39, 150 sq. ft. The total lot area is 197,500 sq.ft., which calculates to a lot coverage of 19.8 %. The building configurations are shown on the accompany- ing plans. The planning principle -.of the project is that of a planned unit development. A planned unit develop- ment concept is desirable in order to take best advantage of the site characteristics by allowing higher densities in certain areas, and allowing the steeper portions of the site to remain undeveloped. Further- more, a larger portion of the site may be designated as common open space. Access to the site has been provided from South 153rd to avoid disruption to the natural vegetation barrier along Southcenter Blvd. The units have been clustered and positioned as close as possible to the access road, thus reducing the amount of grading required, and maintaining the maximum amount of common open space which will serve as a natural landscape barrier. By clustering the units, additional landscape areas can be retained between the units. 3. The proposed development represents a unique condition for several reasons. First, the site is unique. It's steepness in some areas and limited access require zoning that✓can allow maximum flexibility in design. The current zoning does allow that flexibility; however, the proposed land use of the comprehen- sive plan is not proper for this particular site, as further discussed in Section 7. The proposal as planned meets many of the goals and objectives of the comprehensive plan, and is situated in an area that is currently multi - family. Because the project consists only of 58 units, it's effect on traffic, utilities, and public resources will be minor. 5. The project is located in an area that can be considered an area of high natural amenity and development constraint. The natural amenity of this site is the appearance of Tukwila Hill as seen from the freeway and the city below. Certainly, there are other portions of Tukwila Hill which have been developed differently for multi - family development. This project endeavors to maintain the natural appearance of Tukwila Hill by locating all structures on the upper portion of the property, and designating the lower portions of the property, and the steeper slopes as common open space. This common open space will retain all existing trees and vegetation and will provide a visual barrier that will allow this portion of Tukwila Hill to remain visually much the way it is in it's undeveloped state. The other major concern in regards to this property is it's steep slopes. The soils engineering firm of Hart Crowser and Associates has been a member of the design .te!am throughout the preliminary design phase, and will continue through the duration of the project to ensure that all slopes on the property or adjacent to the property are maintained in a stable condition. If slope instability is encountered, approved engineering techniques will be used to stabilize that slope. Accompanying this waiver request is a soils report. Findings to this date indicate that the proposed building can be constructed on this site without problems with slope stability. Waiver Application Attachment • • 6. The following goals and policies support the proposed project. NATURAL ENVIRONMENT Objective 1 Policy A wide andscape buffer ranging in width from 15 feet to 80 feet will be provided on all slopes extend- ing from the front of the buildings to the property line below. Sight lines are such that from the freeway most buildings will not be visible above the tops of the trees. During the foliage months the existing tree cover will provide a dense screening of the project, and during the non - foliage months the build- ings will be partially shielded by conifers. Policy 2 W ere possible, existing vegetation will be retained, including the areas..between buildings. Where natural terrain features are disturbed, natural landscaping will be provided for erosion control and slope stability. Policy 3 No portion of the property will be cleared prior to final approvals. Grading, even in the areas of the buildings, will be kept to a minimum. Objective 2 Policy 1 This project will strive to retain the wooded hillsides to the greatest extent possible. Approximately 40% of the site will remain in it's natural state. Objective 3 Policy I I� I roads within the project have a slope of 15% or less. It is recognized that great care must be exercised when buildirg on slopes in excess of 20 %, with the primary concerns being slope stability and erosion control. No buildings in this project will be located on slopes over 20% without careful geological and structural analysis and design by the applicant and review with the City of Tukwila. Policy 2 The buildings in this project are located such that no views from existing residential units will be affected. The only portion of the property that has the potential for view obstruction is retained as natural open space. Pol i;cy 3 The project will require no new fill to be imported. A certain amount of cut will be required for the roadway construction at the southwestern portion of the property in order to maintain the roadway grade at less than 15%. This cut material will satisfy some minor fill requirements at the northeast end of the property. Minimum grading will be required at the actual building sites. A 'kmajority of the cut material will be removed from the site. i 7. Waiver Application Attachment • (6 - continued) Policy 4 No grading,- filling or excavation will be commenced prior to full approval of the project. During construction careful supervision and planning during grading will avoid unnecessary disruption of land forms. Objective 4 Policy I T ids project has no negative impact on existing stream environments. There are no existing streams on the site.. Policy 3 This project has no negative impact on the water quality of the area's waterways. Sedimentation control methods will be employed during the corstruction period until permanent erosion control measures can be installed. Objective 5 Policy This project will have only minor affect on air pollution. This will be caused 'by certain equipment during construction., and by increased vehicular traffic once the project is occupied. Objective 6 Policy I TTie project design team recognizes the problems associated with steep slope development. Preliminary soil studies have been conducted by Hart, Crowser Associates and these results have been reviewed with structural engineers. Preliminary data indicates that the project as presently conceived can be safely constructed on the site, with no deterioration of slope stability. This will be monitored closely throughout design and construction. Policy 2 The south slope of Tukwila Hill is most certainly a feature of geologic interest to the City of Tukwila. By limiting development to the upper portion of the property and maintaining a natural vegetation barrier on the lower portions of the slope, this project serves to retain the natural characteristics of the site to the maximum extent possible. 2. OPEN SPACE Objective Policy I T iiis project preserves the hillside in a scenic condition. The landscape buffer of existing ;trees and vege- tation that will be left in .it's natural state at the lower portion of the site will buffer the residential area from the freeway, and will provide a visual barrier from the freeway. During the foliage seasons the buildings will be almost totally obscured from view from the freeway, and will be partially screened during the non- foliage season. Policy 2 This project has no adverse effect on the preservation of marshes, ponds, and water courses. There are no marshes, ponds, or water courses on the property. Waiver Application Attachment Policy 3 Active recreation will be provided by Tukwila Park that is adjacent to the site. Policy 4 Passive recreational facilities will be provided as required by the City of Tukwila. Natural open space will constitute 40% of the site. Policy 5 Tukwila Park is immediately adjacent to the subject development, providing the residents excellent passive and active recreation within walking distance. Objective 2 Policy 3 Location of the site does not allow convenient pathway links directly to retail activity. All retail activity is beyond reasonable walking distance from the site with the majority located on the other side of the freeway. Objective 3 Policy 2 This policy is a key factor in the design and development of this project. The building units are clustered at the upper portion of the property, to allow for the maximum amount of open space with which to creat a visual barrier. 3. RESIDENCE Objective I Policy I Tie project is compatible with the other properties in the immediate vicinity which are predominantly multi - family residential. The primary potential incompatability of the site exists with Southcenter Blvd. to the east. It is generally not desirable to locate a residenthdl use immediately adjacent to a heavily traveled roadway. As a solution to this problem, all units will be separated physically from Southcenter Blvd. by a steep slope, and visually by an extensive natural landscape buffer. Policy 2 Tukwila Park borders the majority of the western property line, providing an effective barrier from other residential projects. Policy 3 The development density of this project is compatible with existing and adjacent land uses. Policy 5 The project is compatible with the residential land use already in the area. -3- Waiver April ication Attachment • • Objective 2 Policy I The project does not border on single family residential areas. The only residential projects are multi- family developments to the northwest which, in effect, serve as the transition areas between single family residential to the north, and the proposed project. Policy 2 Vehicular access to the project is on 153rd St. which serves only multiple family residential. 153rd St. i s approximately one mile long, and intersects with 65th Ave. So., which serves as an arterial to residential areas on Tukwila Hill. All traffic is routed to freeways and shopping via Southcenter Blvd. without passing through residential areas. Policy 3 Singe family residential areas are not located adjacent to the project. Objective 3 Policy I An extensive natural landscape buffer will be provided as a visual screen alorg Southcenter Blvd. See site plan. The slope of the terrain along . Southcenter Blvd. will help screen noise, and the height of the units above the road will be helpful as a noise barrier. Policy 2 All units will experience exceptional views to the southeast of the valley and Mt. Rainier. During foliage months the trees that form the visual Farrier will dominate the view, while in the winter months the valley view will be filtered through the trees. Policy 3- All to the project will be underground. Policy 4 The natural open space will be selectively cleared to leave only those species of vegetation that enhance the environment of that open space. A maintenance program will be encouraged to maintain the initial level of landscaping. Policy 5 The project will provide parking as required by the City of Tukwila Building Codes and Ordinances. Policy 6 An internal circulation system will be provided to allow access by all units to the common open space and to the park. See site plan. Policy 7 Passive recreation facilities, including a playground area will be provided in the common open space. Additional access will be provided to the adjacent Tukwila Park. Waiver Application Attachment HOUSING OBJECTIVES AND POLICIES Objective I Policy 2 All 60 units will be sold as condominiums. Objective 2 Policy 2 This project will meet or exceed all building code requirements. • Policy 3 Measures will be taken to adequately insulate the units from traffic noise. Objective 4 The project will incorporate certain crime reducing elements, such as area lighting, and hardware. Additionally, the design of the units is such that there is only limited access to each unit, and very little opportunity to view the interiors of the units. Because one entrance court serves four units, an interaction between neighbors will be encouraged, which will enhance security. 5. TRANSPORTATION /UTILITIES SECTION I - Transportation Objective I Policy 2 All parking and maneuvering by residents of and visitors to the project site will be done on the site proper. Policy 7 The on -site vehicular circulation will comply with requirements for fire department access of emergency vehicles. The project site will have low intensity security /safety lighting throughout the parking /circulation areas. The access to this project will be by improving So. 153rd St. from the end of the existing improvements to the project site, some 180 feet. It should be noted that 67th Ave. So. 30 foot right -of -way lying adjacent to and west of this project site cannot be developed because: 1. The Tukwila Park, some 130 feet south of So. 153rd Street has been developed to the centerline of 67th Ave. So. 2. 100 feet north of So. 153rd Street the existing ground falls to Interurban Ave. So. at a slope too steep to allow vehicular traffic. Waiver Application Attachment SECTION 2 - Utilities WATER SYSTEM Objective 2 Policy 4 The water lines in the subject site will be sized to provide the required fire flow, as determined by Insurance Services Office paper. This water line will connect the existing 6 inch water line in So. 153rd Street, through the subject site, to the existing 12 inch water line in Southcenter Blvd. to ensure adequate water supply. Thewater supply line shall be in an easement to the City of Tukwila, with water meters to each unit at the water line. The buildings will be constructed with sprinkler systems. Fire hydrants will be installed on -site at approximately 300 foot spacing to provide adequate fire protection. SANITARY SEWER SYSTEM Objective 3 A back -lot sewer collection line will be constructed on the down -hill side of the residential units, draining by gravity to an existing sanitary sewer line in Southcenter Blvd. _ STORM DRAINAGE Objective 6 Policy 4 The building roofs facing the on -site roads shall drain into the road storm drainage system, which drains to the south property line. The storm run -off from the building roofs away from the on -site road will be collected in a tight line and will drain to the existing catch basin and pipe crossing Southcenter Blvd., approximately 400 feet north of the project's south boundary. Policy 5 Storm retention basins will be provided as required by the City of Tukwila. Objective 7 The storm run -off quantity and any required retention will be calculated using King County Division of Hydraulics manual and design guides as required by Tukwila City. UNDERGROUND UTILITIES Objective 8 Policy I Tie utility services to this project will be extended underground from the existing underground Puget Power and Pacific Northwest Bell vaults in South 153rd St., some 180 feet west of the project site. ,• ,'Waiver Application Attachment - • • 7. The proposed land uses of the City of Tukwila comprehensi ve land use plan renders the site virtually impossible for development from a practical and financial standpoint. The current residential zoning would only allow about 30 units maximum. Because of site development costs for this property, this will cause residential unit prices to be higher than existing market rates, unless costs can be averaged by a larger but still appropriate number of units. The existing site of 4.68 acres is divided into three different land uses. Almost 50% of the property, or 2.33 acres, is designated as single family residential at 1 -5 units /acre. This portion is the steepest portion of the site and not well suited for sirg le family development. 0.7 acres is designated as office, and while this is consistant with other office developments along Southcenter Blvd., it would require access from Southcenter Blvd., which would be very difficult due to the steep grade, and would be a visual detriment due to the removal of natural existing vegetation, and would increase traffic on Southcenter Blvd. The remaining 1.65 acres is designated as medium density (6 -16 units per acre). A close study of the site will show that conventional lot by lot development is not suited to this site. Dedicated roadways, rear yard setbacks, and maximum lot sizes all serve to severely limit the planner's flexibility in utilizing the site to best advantage. It is our belief that the only reasonable type development for this property is multi - family residential, designed on the principle of a PUD. This would allow greater flexibility and compatability with the site. Because of the high development costs associated with the construction of the roadway and other site improvements, the proposed number of units is considered a minimum to allow a financially feasible project. J -722 March 6, 1980 Robert 0. Birdwell 16705 S.E. 12th Bellevue, WA 98008 i INC HART CROWSER & associates inc. Attn: Mr. Robert 0. Birdwell Re: GEOTECHNICAL ENGINEERING GEOTECHNICAL ENGINEERING Subsurface Exploration and Geotechnical Engineering Study Proposed Park Terrace Condominiums Tukwila, Washington Gentlemen: We are pleased to present herein three copies of the above referenced report. An additional copy has been sent to Lovegren- Loveland Associates. Our explorations indicate that the proposed condominiums will be situated above bedrock (sandstone and basalt) overlain by varying thicknesses of residual overburden and /or talus. Because of the sloping nature of the site, the buildings located over the steeper, portions of the site would require pile support. The remainder could be supported.on- shallow - spread footings founded_ within the near surface rock. -:. We appreciate the_opportunity•to: provide youu -with---these.engineering services.- Should = you have any -questions-regarding-this report or any other - aspects of the project we would _be :pleased to discuss.:.- them-with you at your convenience. Sincerely, HART - CROWSER & ASSOCIATES, INC. GARRY E Project GEH:dw r C HO VI TZ Engineer DESIGN SERVICE BUILDING, 1910 FAIRVIEW AVENUE EAST, SEATTLE, WASH. 98102, (206) 324 -9530 WASHINGTON PLAZA, SUITE 1695, TACOMA, WASH. 98402, (206) 572 -5156 Toll Free From Seattle to Tacoma, 838 -0824 • • SUBSURFACE EXPLORATION AND GEOTECHNICAL ENGINEERING STUDY PROPOSED PARK TERRACE CONDOMINIUMS TUKWILA, WASHINGTON MARCH 6, 1980 J -722 HART - CROWSER & ASSOCIATES, INC. 1910 FAIRVIEW AVENUE EAST SEATTLE, WASHINGTON 98102 J -722 TABLE OF CONTENTS Page No. INTRODUCTION 1 Site Conditions 2 Subsurface Conditions 3 PROJECT DESCRIPTIONS 5 GEOTECHNICAL ENGINEERING STUDIES: CONCLUSIONS AND RECOMMENDATIONS 5 General Foundation Considerations 5 Site Preparation and Temporary Excavations 7 Structural Fill 8 Shallow Foundation Design Considerations 10_ .. _ Pile Foundation Design Considerations 11 Vertical Pile Capacity 11 Uplift Capacity 12 Lateral Pile Capacity 13 Pile Installation 15 Floor Slab -On -Grade 17 Drainage and Backfill Requirements 17 Pressures on Basement-Walls - 18 Considerations for Permanent_Slopes . 20 -.:. ADDITIONAL RECOMMENDATIONS 21 LIST OF TABLES AND FIGURES TABLE I Allowable Vertical Compressive Soil /Pile Capacity 12 TABLE II Allowable Vertical Soil /Pile Capacity 12 TABLE III Lateral Pile Behavior Parameters 14 Figure 1 Site and Exploration Plan Figure 2 Moment Coefficient For Laterally Loaded Pile APPENDIX A FIELD EXPLORATIONS A -1 Test Pits A -1 Borings A -2 Seismic Refraction Surveys A -2 J -722 Table of Contents Con't. Page No. LIST OF FIGURES Figures A -1 Test Pit Logs TP -1 through A -4 through TP -11 APPENDIX B LABORATORY TESTS B -1 LIST OF FIGURES Figure B -1 Grain Size Classification J -722 SUBSURFACE EXPLORATION AND GEOTECHNICAL ENGINEERING STUDY PROPOSED PARK TERRACE CONDOMINIUMS TUKWILA, WASHINGTON INTRODUCTION This report presents the results of a subsurface exploration and geotechnical engineering study for a condominium development which will be located to the southwest of the intersection of Interurban Avenue__and Southcenter Boulevard in Tukwila, Washington. The locations of the buildings comprising the condominium de- velopment and the explorations accomplished for this study are presented on the Site and Exploration Plan, Figure 1. The purpose of this investigation was to assist in the design of the condominium structures by determining the general sub- surface conditions at the site from which conclusions and re- commendations for foundation design and construction could be formulated. The scope_of.work included field explorations, laboratory tests and--geotechnical-engineering-studies. This -- - report has _.been prepared .for_ the exclusive use of Mr. Robert 0. Birdwell for -specific application to this project in accordance with generally accepted geotechnical engineering practices. -. No other warranty, expressed or implied, is made. Field explorations consisted of a series of backhoe excavated test pits, and shallow continuous - flight, hollow -stem auger borings. In addition, a series of seismic refraction traverses were made to determine the rippability of the on -site rock materials. Exploration procedures and results are presented in Appendix A and interpretive logs of the test pits are pre- sented in Figures A -1 to A -4. J -722 .Page 3 variations then appear evident, it will be necessary to re- evaluate the recommendations of this report. Subsurface Conditions Geologically the hill of which the project site is a part is composed principally of the Renton formation. This formation consists of arkosic sandstone, shale and coal. The materials are typically dense but poorly cemented. In general, the sand- stone portion ranges from firmly cemented and hard to uncemented and loose. The Renton formation is considered to be at least 2,000 feet thick. As will be discussed subsequently, the southerly portion of the site is overlain by intrusive basalts (volcanic materials which have pushed their way up through the sandstone and then spread out over the sandstone. In general these basalts are very hard and dense. The rock tends to break into large and small blocks along joints. Varying amounts of forest___duff., small bushes and small and large trees cover the site-. -Referring to Figure 1, three zones of materials were encountered across the site as generally shown on Figure 1. The first area noted as Zone I, principally within the northern half of the project area, are the sandstones com- prising the Renton formation. Test Pits TP -1, TP -2, TP -6, TP -7 and TP -8 indicate somewhat similar conditions in this area. There exists a residual overburden soil zone consisting of weathered sandstone. This soil zone is composed of loose to medium dense, damp, light brown, slightly silty fine SAND. The depth of this overburden layer ranges from 3 to. 6 feet. Below this overburden layer was encountered what appears to be a poorly cemented sandstone consisting of dense to very dense, brown to tan, slightly silty fine sand. This material extended J -722 Page 4 to the bottoms of the test pits (depths ranging from 6.5 to 10.5 feet). Very difficult digging by the backhoe was encountered at these depths. The second primary area of material, Zone II, exists toward the southwestern portion of the site. The material encountered here appears to be the intrusive basalts and metamorphosed sandstones previously discussed. Test Pits TP -3, TP -4 and TP -5 were ex- cavated in this material where the backhoe was only able to excavate to a depth of around 12 feet. It appears that this basalt, which is an igneous (volcanic) material, forced it's way up through the Renton sandstone (the near vertical intrusion is visible in a cut along Southcenter Boulevard) and then spread out over the surface of the sandstone. It is not possible to assess the depth of basalt in this zone. The third major area of material, Zone III, exists towards the central and lower southeast portions of the site. This zone is somewhat of - a transition between the-first -two. The test pits excavated in this area - (TP -9;- TP -10 and possibly- TP -11) suggest--that- some of the upper basalt -materials have spalled from the upper portions - -of the site and have been deposited in this area as talus overlying the sandstones comprising the first zone. Test Pit TP -9 encountered this very dense basalt frag- ment talus to a depth of 3 feet below which was encountered the weathered sandstone (grading from medium dense to very dense or hard). Test Pits TP -10, and TP -11 indicated 52 and 2 feet respectively, of this very dense talus. These depths also cor- respond to the refusal depth for the backhoe. It would appear (although there is no way to conclusively discern) that the talus material grades into the in -situ basalt as one proceeds in a generally southwesterly direction. J -722 Page 5 No groundwater was encountered in any of the explorations ac- complished for this study. Some groundwater could be present near the ground surface during the wetter seasons of the year. PROJECT DESCRIPTION We understand that the proposed condominium development will consist of six structures as indicated on the Site and Explora- tion Plan, Figure 1. For reference purposes within this report we have numbered the units as shown in the figure. In general the units will be primarily of wood frame construction. The structures will have three or . four floors which will be staggered in plan so as to conform as much as possible to the angle of the existing slope. Drawings supplied to us by Jim Stapper of Lovegren - Loveland Associates indicate that some cuts would-be made to provide level areas for a roadway as indicated in Figure 1. GEOTECHNICAL ENGINEERING - STUDIES: - CONCLUSIONS AND RECOMMENDATIONS _ General-. Foundation _Considerations. _ As previously indicated the site slopes at varying degrees pri- marily toward the north and west. In our opinion, problems associated with sliding stability could be encountered by founding the proposed condominium structures on shallow spread foundations within the overburden soils overlying the sandstone (Zone I) or within the shallower portions of the basalt talus overlying the sandstone (Zone III). Shallow spread footings would, in our opinion, be appropriate in areas where the in -situ basalt and metamorphosed sandstones are present (Zone II), near the surface. • • J -722 Page 6 In Zones I and III it is our opinion that the most suitable form of foundation will be one that transfers the structural loads to the underlying very dense sandstone soils. We there- fore recommend that piles be used in these areas. We do not feel, that it will be feasible to drive displacement (timber, precast, concrete, etc.) piles to suitable depths within the site soils. Low displacement piles, such as steel H -piles could probably be driven to a sufficient depth within the dense weathered sandstone encountered in the test pit and boring ex- plorations. However, extreme difficulty would be encountered in attempting to drive through the surficial basalt and meta- morphosed sandstone talus in Zone III. These materials would probably need to be excavated prior to driving of the pile, thus requiring two separate activities for installation. In addition, it is possible that harder, more heavily cemented sandstone could be present below the depths of our explora- tions. In this type of material it might not be possible to drive the H- piles : to a suitable _ depth;.therefore- H- piles - -could ._ . also - prove - -to be. - not _feasible. An-alternative to driven piles is -a cast-in-place-cement grout-. pile. These piles are most usually'installed using an auger - cast method. This is accomplished by drilling to depth with a continuous - flight, hollow -stem auger and pumping cement -sand grout under pressure through the hollow auger as it is withdrawn resulting in a cast -in -place pile. Immediately following with- drawal of the auger, reinforcing steel can be placed into the fresh grout column to provide lateral and tension capabilities. Problems could be encountered with augering of the basalt and metamorphosed sandstone talus. Difficulty might also be en- countered in augering of the dense weathered sandstone at depths • • below the bottoms of our explorations. For these situations the holes for the piles could be advanced using a rotary drilling technique. Rotary drilling (which is a more positive cutting method) involves the cutting of the soils or rock using a large bit with the aid of a mixture of water and drilling "mud" delivered to the drill bit under high pressure. Once the suitable design depth has been reached, the cased or uncased hole can be pumped full of grout. Reinforcing steel (in the form of re -bar or H or I steel sections) can be placed in the fresh cement column. In our opinion rotary drilling installation of the pile foundations would tend to be the most reliable form of foundation construction. Site Preparation and Temporary Excavations Site preparation should consist of stripping of the forest duff and organic topsoil within areas to support the buildings and pave- ment sections.-.. .Trees _.in. these . areas should be . cleared_.and _.grubbed - As indicated earlier., some cuts_will._be.•made for the roadway shown in- Figure 1. Some cuts will also be made so as to "notch the condominium units into the hillside. In January of 1979 a series of seismic refraction traverses were made at the site. Details of this exploration and testing method are presented in Appendix A. Seismic velocities were determined within the dense sandstones and basalt at the site. Velocities of 5,000 to 6,000 feet per second (fps) were recorded in the sandstones indicating that this material can probably be ripped with conventional equipment. Seismic veolocities in the upper fractured basalt of 3,100 to 3,200 fps were recorded indicating that this material also can most probably be ripped J -722 Page 8 near the surface. Blasting could and probably would be required for deeper excavations in the basalt, however. Temporary excavation slopes should be made the responsibility of the contractor to provide safe working conditions, since he is continuously on the site to observe the nature of the materials being excavated, including groundwater conditions at the time of construction. Following stripping and excavation to the required subgrade eleva- tion, areas which are to support slab -on- grade, paved surfaces, or receive structural fill should be prerolled to a nonyielding compact surface. We recommend that prerolling be accomplished with a relatively heavy vibratory roller (minimum 4,000 pounds static weight) such that the upper 12 inches of exposed, non - organic, natural soils are compacted to at least 95 percent of the modified Proctor maximum dry density (ASTM D1557 -70) beneath building areas and paved surfaces. To achieve this de- gree of-compaction it may be necessary- to = scarify the upper:_ in- situ- soils- and adjust these materials- for prope-r-=-moisture-con- tent. The surface should be observed during prerolling to de tech the _presence of pockets-.of soft or loose soils which, if encountered, should be removed and backfilled in accordance with the recommendations for structural fill. Obviously, those areas which are excavated down to intact rock do not need to be prerolled. Structural Fill Any permanent fill placed within building areas and beneath paved surfaces should be placed as structural fill. The structural fill should be placed after removal of any loose or soft soils encountered during site preparation activities and after the stripped surface has been prerolled, if deemed feasible. J -722 Page 9 The structural fill should be placed in lifts not exceeding 10 inches and thoroughly compacted to at least 95 percent of the modified Proctor maximum dry density beneath the building areas and 92 percent in paved and parking areas, as determined by ASTM D1557 -70 Test Procedure. The suitability of excavated site soils for comapcted structural fill will depend on the gradation and moisture content of the soil when it is placed. As the amount of fines (that portion passing the No. 200 mesh sieve) increases, the soil becomes increasingly sensitive to small changes in moisture content and adequate com- paction becomes more difficult to achieve. Soils containing more than about 5 percent fines cannot be consistently compacted to a dense, nonyielding condition and achieve a safe bearing cap- acity equal to or above our recommended value when the water content is greater than optimum. Grain size analyses indicate that the dense weathered sandstone soils and sandstone derived overburden soils contain. between 20 to 30 percent —fines making-it suitable for placement during-- - periods of dry weather. Because it has more than 5 percent. fines it is not, in our opinion, suitable for placement -during___ periods of wet weather. If it is required to import structural fill material to the site it should consist of a reasonably well - graded sand or sand and gravel. The maximum particle size within the structural fill should be about 6 inches. The fines content (soil finer than a No. 200 mesh sieve) should be limited to less than 5 percent (based by weight on the minus 3/4 -inch fraction using the wet sieve analysis), and be nonplastic if placed during wet weather. The fines content may be as much as 30 percent when placed druing the dry season, provided the moisture content is near optimum. The optimum water content is that which allows J -722 Page 10 the most dense compaction of a soil under a given compactive effort. Prerequisite to fill control is a determination of the com- pactive characteristics from representative samples. Samples should be obtained from borrow sources as soon as work begins A study of the compaction characteristics should include de- termination of optimum and natural moisture contents of these soils at the time of construction. We recommend that an experienced soils technician be present during filling operations to monitor compaction procedures and make field density tests. Shallow Foundation Design Considerations As previously indicated it is our opinion that shallow spread footings would provide the most suitable foundation support within the Zone II area at the .southwestern corner of the site. This specifically involves buildings-_Nos. ..5 and 6 as indicated in Figure 1. It should be noted that our delineation of the limits of this area is only approximate as access to the entire area is not possible at this time. The validity of the re-_ commendation to use shallow foundations throughout each of these two buildings should be verified by an experienced geotechnical engineer at the time of construction. Continuous strip and isolated column footings should have mini- mum widths of 18 and 24 inches respectively. All footings should be embedded within the intact basalt to a depth of at least three (3) feet. Footings meeting these criteria can be designed for an allowable bearing stress equal to 8,000 pounds per square foot (psf) . • • J -722 Page 11 The bottoms of each footing excavation should be observed by a qualified soils, technician to. confirm adequate bearing sur- faces. Although precise structural loading information is not now abailable, we anticipate that maximum total and differential settlements of these structures would not exceed 1 and 2 inch, respectively. Pile Foundation Design Considerations Vertical Pile Capacity - As indicated earlier it will be necessary due to considerations of stability to support the condominium structural loads at depth. It is our recommendation that all piles be embedded within the underlying dense to very dense sandstone =a distance .of 15 feet. Assuming a 5 to 6 feet thickness - of overburden and /or talus material this would correspond to a total depth from existing grades equal to 20 to 21 feet. Since cuts of various depths will be made prior to pile installation, the.actual.required pile penetration depth should be determined in :the field- at each location:- In no case.. should: any =pile be . installed --to a depth less_.than 15 feet.. It is possible that - talus-(basalt and metamorphosed -sandstone gragments) could be - encountered in the area of- Building -No.-4 and portions_of Building _ No. 3. Where an excess of ten (10) feet of talus is encountered the piles should extend into the underlying sandstone by a dis- tance equal to the remainder of required 20 feet total embedment depth. The tips of the piles, in any case, should be firmly embedded within the very dense sandstone. The tips should not be allowed to terminate within'the weathered overburden which, as previously discussed, tends to overly the dense sandstone. Typical cast -in -place pile diameters range from 10 to 16 inches. Soil /pile capacities have been valuated using a factor of safety equal to 2.5 which is generally accepted engineering practice. J -722 Page 12 Predicated on a minimum depth of embedment of 15 feet within the sandstone the following vertical soil /pile capacities can be used for design; TABLE .I. Allowable Vertical Compressive Soil /Pile Capacity Pile Diameter Allowable Vertical Compressive Capacity (Inches) .. .(Tons). ... 10 32 12 43 14 57 16 72 It is important to note that these vertical capacities represent the strength which can be mobilized by the soil and do not take into account the allowable loads which can be transmitted within the pile itself.. Maximum .. total and differential settlements of the pile supported •structures should - not.,exceed.._l_ and_ 2 respectively. These values however-, -should be_verified when-the final structural- load configurations have been established.- Uplift Capacity - Design values for vertical soil /pile uplift capacity for the same pile diameters are listed below. TABLE II Allowable Vertical Soil /Pile Capacity Pile Diameter Allowable Vertical Uplift Capacity (Inches) (Tons) 10 10 12 12 14 14 16 16 • • J -722 Page 13 It should be noted that these values are based on the available friction (or adhesion) between the soil and pile and do not take into account any limitations in the tensile strength of the pile itself. Therefore the tensile capacity of the pile will have an upper bound equal to the smaller of the soil -pile strength and the structural tensile strength of the pile itself, (with a suitable structural factor of safety). Lateral Pile Capacity - The lateral resistance which could be developed by the soil surrounding the embedded portion of a single pile (assuming a rigid pile cap) has been evaluated by elastic considerations. A constant of horizontal subgrade reaction (nh) equal to 25 pounds per cubic inch for the dense talus and /or sandstone was used which will control the lateral pile behavior. Using this value and values for structural stiffness (EI)* of the piles, the relative stiffness factor (T= EI /nh ) was computed and the values are presented in Table III below. To limit the amount =of _lateral _pil-e..deflection -at the ground. line it is recommended-that-embedment of -at _.east four -times . the relative stiffness factor, -T, be 'achieved. .._With such .embedment depths,--the-ultimate .resistance to an applied - lateral load-is governed primarily by the strength characteristics of the pile and not the strength of the soil. For the purpose of this study, we have assumed that all pile cap /slabs would be at or below the ground surface and would be designed rigidly. Based on the assumption of a rigid pile cap, it can further be assumed that any lateral load transmitted to the pile cap would be evenly distributed among all the piles contained within the group below that pile cap. Based on this *Values of EI are based on the properties of the concrete and do not take into account the added stiffness of reinforcing steel. • • J -722 Page 14 and the preceeding values of relative stiffness, T, of the pile, numerical coefficients can be developed, which when multiplied by the lateral loads on each pile would give the resultant lateral deflection at the pile cap. The lateral deflections could be described by the following expression: Deflection of a single pile, A (inches) = (Op) (Pn) where Lp = lateral deflection coefficient (See Table III) Pn = applied lateral load on each individual pile (kips) It is important to note that the above formula represents the movement of a single pile. If all piles in a group are equally loaded laterally, then it also represents the movement of the pile group. However, certain factors, such as spacing of piles within the group and vibrations, can effect these movements. These affects will be discussed subsequently. TABLE III Lateral_ Pile Behaviorl Parameters': Depth to Point Pile - EI - T of - Fixity - 0 p lb- in2x109 (Feet) (Feet) (Inches) 10 -inch Diameter 1.47 3.0 9.2 .030 Concrete 12 -inch Diameter 3.06 3.5 10.7 .022 Concrete 14 -inch Diameter 5.67 3.9 12.1 .016 Concrete 16 -inch Diameter 9.65 4.3 13.3 .014 Concrete Moment coefficients which could be used to describe the bending moment distribution within the pile as a result of any applied 1 • J -722 Page 15 lateral thrust at the pile cap are presented as Figure 2. Using this coefficient, the resulting bending moment at any particular depth within a single pile may be computed as: Moment at any depth, Mz (kip -feet) = (Kmp) (T) (Pn) where T is in feet and Pn is in kips The design criteria are an idealized estimation of the deflection at the ground surface and the magnitude and distribution of maximum bending moments. We recommend the design criteria be utilized with the actual anticipated loads to determine the deflections and maximum moments. These calculated values should be analyzed with respect to the tolerable deflections of the structure and the strength of the pile material (with a suitable factor of safety) to resist the moments and shears. It should be noted that the above formulations do not contain a factor of safety. Further, a number of circumstances can alter the actual deflection values obtained in the field as compared to the_ calculated values_ as previously mentioned._ For-instance, in regard to groups _ of _piles , at the minimum pile spacing,--actual .. - . pile deflections in a group may be almost twice that calculated for an individual pile. The effect -s of group action tend_to disappear when piles are spaced eight or more diameters, center to center, in the direction of the load and more than three diameters in a direction horizontal to the applied load. Piles subjected to repetitive, cyclic loading may result in deflection magnitudes up to twice that of a pile subjected to a static load. Pile Installation We recommend that pile spacing within groups be no less than three pile diameters on center. • • J-722' Page 16 The recommended allowable pile capacities presented previously were associated with a particular penetration into the bearing strata. Based on the explorations on the site, the re- quired depth at those locations could be determined. However, the exact elevation and nature of the bearing layer between the explorations is not known and can only be presumed. For this reason, we strongly recommend the installation of all piles be observed by Hart - Crowser & Associates, Inc. Our re- presentative could observe the contractor's operation, collect and interpret the installation data and determine the required pile penetration depth. All piles should be installed to their design tip elevation. We believe that the top of the bearing layers should be evident by careful observation of the auger penetration rate and cor- relation with the subsurface explorations on the site. The installation of cement grout piles sometimes raises the question of what is an acceptable pile. As the complete -pile below ground cannot be observed,— judgement -rand experience must be used, in our opinion, as the basis for determining the ac- ceptability -of_a pile.. This not only includes the-observer's experience, but also that of the pile contractor who is most familiar with such installations. Thus, we would utilize our experience with normal operation procedures from previous cast - in -place pile installations and those established by the contractor for the current job, including installation sequence, grouting pressure (if augercast methods can be used) and quantity of grout used per pile. Variations from the established normal pattern, such as low grout pressure, excessive settlement of grout in the completed pile, etc., would make that pile(s) susceptible to rejection. In order to provide an evaluation of pile in- stallations, we recommend that the contractor be required to • • J -722 Page 17 provide a pressure gauge in the grout line (for augercast opera- tions) and some means of determining the quantity of grout used per pile. In many cases, the rotary action may tend to disburb the soils at the bottom of the drilled hole resulting in decreased end bearing capacity. In order to minimize the negative effects of this disturbance, we recommend that the pile contractor be required to thoroughly flush the drilled hole prior to pumping of the cement grout (for rotary operations). Prior to construction we recommend that pile installation tests be performed to determine if augering methods or rotary methods are more appropriate. Floor Slab -On -Grade Where appropriate the lower interior floors of the condominium structures could be constructed as slab-on-grade above the dense in -situ soils., comapcte-d- subgrade, or •structural .fill..-We re- commend that the floor -slab be underlain by a minimum 4 inch layer of clean, well - graded sand and gravel. to .provide -a drainage course and capillary break. The sand and gravel layer should conform to the following gradation requirements: % Passing 2" square opening 95 to 100 % Passing 4" square, opening 30 to 60 % Passing U.S. No. 8 sieve 20 to 50 % Passing U.S. No. 50 sieve 3 to 12 Passing U.S. No. 200 sieve 0 to 2 Drainage and Backfill Requirements Our opinion is that during the wetter portions of the year ground- water could seep downslope and come in contact with the subgrade walls. To protect subgrade walls and floors from moisture and • • J -722 Page 18 to avoid the buildup of hydrostatic pressures., we recommend that an external drainage system be installed around the entire structure adjacent to the subgrade walls. Backfill material within 18 inches of an exterior wall and extending to within about 1 foot of the ground surface should consist of clean, free - draining granular material such as that conforming to the preceding requirements for a capillary break beneath slab -on- grade. The backfill should be sealed at the ground surface with a mini- mum of 1 foot of impervious soil in unpaved areas to prevent surface water from entering directly into the subdrain system. The subdrains (with cleanouts) should consist of at least 4 inch perforated pipe with perforations placed down. The free - draining backfill adjacent to the exterior walls should be continuous to envelop the subdrains for at least 6 inches in all directions. Roof drains should not be connected to the subdrains. All backfill placed behind subgrade walls or around foundation units should be compacted to at least 95 percent of the maximum density obtained by the modified Proctor procedure. Final site grades should be designed to carry away surface water from the structure so that they_ will not accumulate and pond-next—to the structure. The drains should be connected to suitable outfalls and should not be permitted to drain onto the existing slopes. Pressures on Basement Walls The lateral soil pressures on subgrade or foundation walls back - filled on one side only will primarily depend on the degree of compaction and amount of lateral movement permitted at the top of the wall during backfilling operations. If the walls are free J -722 Page 19 to yield at the top an amount equal to approximately 0.001 of the height of the wall, the soil pressures will be less than if the movement is more limited by stiffness or by construction of the structural floor network prior to backfilling. Utilizing the recommended backfill compaction of 95 percent modified Proctor maximum density, we recommend that an equivalent fluid pressure of 35 pcf and 55 pcf be used for yielding and nonyielding subgrade foundation walls, respectively. For walls backfilled on the interior side, an equivalent fluid pressure. of 350 pounds per cubic foot could be used for passive resistance. These equivalent fluid pressures are based on the assumption of a uniform backfill and no buildup of hydrostatic pressures behind the wall. The subgrade walls should also be designed for additional lateral soil pressure due to any vertical loads likely to occur within a horizontal distance of the wall equal to the depth of the wall below the higher adjacent floor slab or exterior finished grade. In this regard, a lateral load equal to 35 percent of a vertical surcharge pressure should be considered to act against the. wall._ The location on the wall that the additional pressure or load can be-considered to be acting may be estimated by projecting a line_or surface downward and outward at a 1:1 slope from the outer limits of the applied vertical load to its intersection with the wall. Also, to prevent the buildup of lateral earth pressures in excess of the above design pressures, overcompaction of the fill behind . the wall should be avoided. This can be accomplished by placing the backfill within 18 inches of the wall in lifts not exceeding 6 inches in loose depth and compacting with hand - operated or small self - propelled equipment. J -722 Page 20 Considerations for Permanent Slopes In our opinion, the following guidelines should be used in the design of permanent cut slopes. 1) Cut slopes made within the loose to medium dense overburden soils should be made no steeper than two horizontal to one vertical (2H:1V). Cut slopes made within the basalt talus and metamorphosed sandstone talus should be made no steeper than one and one -half horizontal to one vertical (12H:1V). 3) Cut slopes within the intact basalt or sandstone should be made no steeper than one horizontal to one vertical (1H:1V). 4) Overall slopes for cut slopes greater than 10 feet in vertical height should be no steeper than one and one -half horizontal to-one vertical (12H:1V) In our opinion, the greatest possible risk associated with slope _ stability at this site might be due to minor localized _spoiling_: of unprotected slopes. It is our recommendation that all slopes be graded such that surficial groundwater will flow evenly and not result in erosion. All cut slopes within soils should be provided with positive protective foliage such as grasses or shrubs. All exposed basalt or metamorphosed sandstone slopes should be scalped of any loose blocks of material. From information supplied to us at this time there do not appear to be plans for placement of fill over the existing slopes. We J -722 Page 21 do not feel that any additional fill materials should be placed out over . any of the existing slopes without conducting detailed stability analyses by a qualified geotechnical engineer. It is imperative to note that our analyses have been based on topographic information supplied by Lovegren- Loveland and Associates which has been reproduced .and presented as Figure 1 within this report. It should also be pointed out that our field observa- tions have indicated misleading simplifications in preparation of the topographic contours on which our analyses have been based. We feel that detailed surveys at each building location should be prepared during the final design stages of the project. At that time the appropriateness of the recommendations contained within this report can be reviewed and any changes can be made. ADDITIONAL RECOMMENDATIONS It is recommended that Hart - Crowser & Associates, Inc. be pro- vided the opportunity for a general review of final design and specifications in order that earthwork and foundation recommenda--: tions may be properly interpreted and implemented in the.design and specifications. It is further recommended that Hart - Crowser & Associates be retained to provide soil engineering services during construction of the foundation phases of the work. This is to observe com- pliance with the design concepts, specifications or recommenda- tions and to allow design changes in the event that subsurface conditions differ from that anticipated prior to start of con- struction. It is especially important that Hart - Crowser be re- tained to observe installation of cast -in -place piles and to inspect the surface of footing excavations. J -722 Page 22 HART - CROWSER & SSOCIATES, INC. 1/.!:-.Ye GARRY E. HORVITZ Project Engineer JOHN C. CROWSER, P.E. Vice - President GEH:JCC:cb SITE A D EXPLORATION FLAN uss •••------" \ 1 `tip ‘1S-3, �.•.• w� 1 ::a f 1 .:7u AVE. v" 1 I 1 1 ii 1 L10 / TP -3 l i ZONE III 60 40 20 0 le0 1,0 :0 :S- 60 120 GTs �■ scale in feet ZONE II LEGEND ® Boring Location and Number 13 -1 6in Test Pit Location and Number TP -3 S-2 • Seismic Traverse Location and Number • J- 722 July 1979 HART- CROWSER a ossocicies inc. Figure 1 MOMENT CIPEFFICIENT FOR LAfE RALLY LOADED PILE (Assuming Rigid Pile Cap at Ground Surface ) 0 1- a w 3 4 -1.0 -.8 -.6 -.4 -.2 MOMENT COEFFICIENT, KMP MOMENT, M = KM X P X T P WHERE: 0 .2 KM = MOMENT COEFFICIENT FROM ABOVE P P = APPLIED LATERAL LOAD T = RELATIVE PILE STIFFNESS WITH RESPECT TO SOIL J -722 July 1979 HART - CROWSER B ossociotes inc. Figure 2 • Test Pits ' Eleven test pits were excavated with a tractor - mounted backhoe at the approximate locations shown on the Site and Exploration Plan, Figure 1. All explorations were coordinated in the field by Mr. Scott Wright, engineering geologist from our firm, who continuously observed excavation and sampling of the test pits. During test pit operations the project geologist collected representative bag, jar and Shelby tube samples of each lithology encountered. These samples were then transported to our labora- tory for further classification and testing. A descriptive log of the strata encountered in each test pit was prepared. The logs of Test Pits TP -1 through TP -11 are presented on Figures A -1 through A -4. J -722 Page A -2 Borings Two borings were advanced at the locations shown on Figure 1 using a small continuous - flight, hollow -stem auger mounted on an all terrain tracked vehicle owned by our firm. The borings were used as probes to determine the depth to firm bearing material. Both borings indicated approximately six feet of loose to medium dense silty fine and fine to medium sand overlying very dense but friable sandstone consisting of slightly silty fine and fine to medium sand. Both borings met refusal at a depth of 6.5 feet. Seismic Refraction Surveys Three seismic refraction traverses were made in areas indicated in Figure 1. The seismic refraction test method consists of measuring the travel time through the ground of a compression shockwave applied by the impact of a sledge hammer and detected some distance away by a sensitive transducer (geophone). The seismic traverse consists of aline of impact points at varying distances from the geophone. - .Information -which can be gained from the seismic tests include apparent depth._to bedrock and the approximate seismic velocity of the materials through which the shock waves travel. These seismic velocities can be correlated with other information to evaluate the need for blasting sub- surface materials for removal or if conventional ripping methods would be sufficient. Traverse T -1 (northeast corner of the site) indicated the presence of approximately 12 feet of weathered sandstone overlying apparently intact sandstone. The results indicate that the depth to bedrock is, for the most part, highly erratic. The traverses indicate a seismic velocity in the sandstone of around 5000 to 6000 feet per second (fps). These velocities indicate that the sandstone is most probably rippable. J -722 Page A -3 Traverses T -1 and T -2 were conducted over the basalt in the southern portion of the site. We were not able to determine the thickness of the basalt layer due to its higher density. (Seismic refraction tests cannot determine layer thickness when a dense layer overlies a less dense layer such as basalt over sandstone). Seismic velocities in the upper fractured basalt of 3100 to 3200 fps were recorded indicating that this material also can most probably be ripped near the surface. Blasting could be required for deeper excavations in the basalt, however. TEST PIT L.TP -I Sample Water Other Depth Content Tests feel 0 SOIL INTERPRETATION Ground Surface Elevation Approximately FOREST DUFF Feet 2 •'� 14 3 4 5 6 14 7 8 9 11 — 12 — 13 — 14 — 15 TEST PIT LOG TP-2 MEDIUM DENSE, DAMP, LIGHT BROWN, SLIGHTLY SILTY FINE SAND, DENSE TO VERY DENSE, DAMP, BROWN, VERY FINE TO FINE SAND (PARTIALLY CEMENTED SANDSTONE). BOTTOM OF TEST PIT 10,0 FEET COMPLETED 11/1/78 Sample woter Other Depth - SOIL INTERPRETATION Content Tests feet % Ground -- Surface Elevation Approximately Feet 15 0 25 3 10 11 12 13 14 15 :i LOOSE TO MEDIUM LOOSE. DAMP, BROWN, SILTY, FINE SAND WITH SCATTERED ROOTS. DENSE. DAMP. DARK BROWN. SLIGHTLY SILTY FINE SAND WITH SCATTERED SANDSTONE AND BASALT FRAGMENTS WITH OCCASIONAL SCATTERED ROOTS AND COAL SEAMS. BOTTOM OF TEST PIT 10.5 FEET COMPLETED 10/1/78 NOTE: Soil descriptions are interpretive and actual changes moy be gradual. J -722 July 197, HART- CROWSER 9 associates inc Figure A-1 TEST PIT LO•TP - 3 Sample Woter Other Depth Content Tests feet 21 0 SOIL INTERPRETATION Ground Surface Elevation Approximately Feet 2 — 3— 4- 5— 6— 7— 8— 9— 10— TEST PIT LOG TP- 4 VERY DENSE. DAMP, BROWN, BASALT ROCK, WITH A MATRIX OF DAMP, BROWN, SILTY FINE SAND. BOTTOM OF TEST PIT 1.5 FEET. COMPLETED 11/1/78 (BACKHOE REFUSAL, BASALT ROCK) Somple Water Other Depth SOIL INTERPRETATION Content Tests feet % Ground Surface Elevation Approximately Feet 2 3- 4- 5— 6- 7- 8- 9- 10 - TEST PIT LOG TP - 5 VERY DENSE, DAMP, BROWN, BASALT ROCK WITH A MATRIX OF DAMP, BROWN, SILTY FINE SAND BOTTOM OF TEST PIT 2.5 FEET COMPLETED 11/1/78 (BACKHOE REFUSAL, BASALT ROCK) Somple Water Other Depth SOIL INTERPRETATION Content Tests feet 0 1 Ground Surfoce Elevotion Approximately Feet VERY DENSE. DAMP, BROWN, BASALT ROCK WITH A MATRIX OF DAMP, BROWN, SILTY FINE SAND. 2 BOTTOM OF TEST PIT 1.5 FEET COMPLETED 11/1/78 3 ( BACKHOE REFUSAL, BASALT ROCK) 4 5 6 7 8 9 I0 NOTE: Soio descriptions are interpretive and actual changes moy be product. Woter level, if indicated, is for date indicoted and will probobty vary with time of yeor. J -722 HART — CROWSER July 1979 9 associates inc. Figure A — 2 TEST PIT LO P - 6 • Somple Woter Other Depth SOIL INTERPRETATION Content Tests fee Ground Surface Elevation Approximately 170 "9O 16 12 0 Feet + 5 FEET LOOSE TO MEDIUM DENSE, DAMP, BROWN. SILTY VERY FINE SAND WITH OCCASIONAL SCATTERED ORGANICS. (TOPSOIL ZONE). 4 5 6 • 4 9 - 10 - TEST PIT LOG TP-7 DENSE TO VERY DENSE. MOIST. REDDISH TAN, SLIGHTLY SILTY FINE SAND, SLIGHTLY CEMENTED..(WEATHERED SANDSTONE) BOTTOM OF TEST PIT 8.0 FEET COMPLETED 7/5/74 • Sample Water Other Depth SOIL INTERPRETATION Content Tests feet Ground Surfoce Elevation Approximotely 162 Feet + 5 FEET 19 20 8 9 10 TEST PIT. LOG TP-8 LOOSE TO MEDIUM DENSE, DAMP. BROWN. SILTY VERY FINE SAND WITH SCATTERED ORGANICS. (TOPSOIL ZONE) DENSE TO VERY DENSE. MOIST, REDDISH TAN, SLIGHTLY FINE SAND. (WEATHERED SANDSTONE) BOTTOM OF TEST PIT 7.0 FEET COMPLETED 7/5/79 Sample Woter Other Depth SOIL. INTERPRETATION Content Tests feet 0/0 Ground Surfoce Elevotion Approximately 160 Feet + 5 FEET 13 9 3 5 7 - 8 - 9 10 - ••••!•!•,•,4■-'• LOOSE TO MEDIUM DENSE. DAMP. BROWN, SILTY, VERY FINE SAND WITH OCCASIONAL SCATTERED ORGANICS. DENSE TO VERY DENSE. DAMP, REDDISH TAN, SLIGHTLY SILTY. FINE SAND (PARTIALLY CEMENTED). (WEATHERED SANDSTONE) BOTTOM OF TEST PIT 6.5 FEET COMPLETED 7/5/79 NOTE: Soil descriptions ore interpretive ond octuol chonge% moy be groduol. Woter level, if indicated, is for date indicated and will probobly vary with time of yeor. J - 722 July 1979 HART-CROWSER a ossociotes inc. Figure A - 3 1 1A 2 TEST PIT LOG ATP - 9 Sample Water Oth ' Depth SOIL INTERPRETATION • Content Tests feet Ground Surface Elevation Approximately 152 Feet 0 � -- VERY DENSE, DAMP, BROWN, SILTY, SANDY BASALT 31 1 ROCK. (TALUS) ± 5 FEET POCKET 18 18 4- 5- 6- 7 - 8- 9- 10 POCKET — MEDIUM STIFF, MOIST, BLACK, SLIGHTLY CLAYEY SILT WITH SCATTERED ORGANICS. MEDIUM DENSE TO DENSE, DAMP, LIGHT REDDISH BROWN, SLIGHTLY SILTY, FINE SAND (WEATHERED SANDSTONE). HARD, DAMP, LIGHT REDDISH GRAY, SLIGHTLY SANDY SILTSTONE (WEATHERED SILTSTONE). TEST PIT LOG TP -I0 BOTTOM OF TEST PIT 10.0 FEET COMPLETED 7/5/79 Sample Water Other Depth SOIL INTERPRETATION Content Tests feet r , °/, O Ground Surfoce Elevotion Approximately 140 Feet ± 5 FEET TEST PIT Sample 5; 6- 7- 8- 9- 10 - LOG TP -II Water Other Depth Content Tests feet 0 2 3 4 5 6 7 8 9 10 VERY DENSE, DAMP, BROWN, SILTY, SANDY, BASALT TALUS (TALUS). BACKHOE REFUSAL AT 5.5 FEET COMPLETED 7/5/79 SOIL INTERPRETATION Ground Surfoce Elevotion Approximately BASALT TALUS 150 Feet + 5 FEET BACKHOE REFUSAL AT 0.5 FOOT COMPLETED 7/5/79 NOTE : Soil descriptions ore interpretive and actual changes moy be product. Water teel, if indicated, is for dote indicoted and will probobly vary with time of year. J -722 July 1979 HART - CROWSER a associates inc. Figure A- 4 • J -722 APPENDIX B LABORATORY TESTS All the jar and Shelby tube samples obtained from the borings and test pits were visually reexamined in our laboratory to refine the classification made in the field. The degree of moisture in the sample (whether it was dry, moist or wet), the approximate percentage of fines in the sample, and the relative plasticity of the fines were particularly noted. In addition, the natural water content was determined on selected samples for the purposes of (1) indentification and correlation of the soils, and (2) providing basic engineering properties. Natural water contents are presented in the logs of borings and, where applicable, on other laboratory test results. Grain size analyses were performed on selected samples of the natural materials in general accordance with ASTM D422 -63. The results of the grain'size analyses are presented in Figure B -1. GRAIN SIZE CL.SIFICATION t 100 90 80 70 T 60 50 40 d a_ 30 20 10 0 Sieve Analysis Hydrometer Analysis Size of Opening in Inches , Number of Mesh per in., US Standard Groin Size in mm P RI N - - ` n 0 0 0 0 0 0 10 8 m ID O O O O O 0 0 0 O O 0 0 0 0 o 0 N 00 0 0 0 0 O m ,D P r, N 0 CO 10 q. , N - R " ¢ vt N Groin Size in Millimeters CO 0 0 0 O 0 1 O O 0 9 8. Cobbles Course 1 Fine Course I Medium I Fine Fines Grovel T --- y - N. ', ,.. \ 1 TP -1 S -1 -- -- TP -1, 5-2 \ ` 1 ll 1 1 1 1 1 1 1 1 1 1 1 1 1 1 11. 1 1 1 1 1 1 1 I J U 0 0 o 0 N 00 0 0 0 0 O m ,D P r, N 0 CO 10 q. , N - R " ¢ vt N Groin Size in Millimeters CO 0 0 0 O 0 1 O O 0 9 8. Cobbles Course 1 Fine Course I Medium I Fine Fines Grovel Sand Sample Depth -ft U.S.C. Classification TP -1 1.2 — SM SILTY, FINE TO MEDIUM SAND. S -1 5.0 (SM OR SW?) 10 20 30 40 50 60 70 80 90 JasJDOD jUaDiad Nat. Atterberg Limits W.C. % •LL PL PI 14% TP -1 5.0 — SM SILTY, FINE TO MEDIUM SAND. 14% S -2 10.0 J - 722 July 1979 HART- CROWSER 8 associates inc. Figure B - I