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HomeMy WebLinkAboutTrans 2014-06-09 Item 2A - Discussion - 2014 Bridge Inspections - 196th-200th Street Bridge Repair Using King County Discretionary AssistanceCity of Tukwila Jim Haggerton, Mayor INFORMATIONAL MEMORANDUM TO: Mayor Haggerton FROM: Bob Giberson, Public Works Director By: Grant Griffin, Senior Program Manager DATE: June 6, 2014 SUBJECT: 2014 Bridge Inspections - 196th - 200th Street Bridge Repair Project No. 91410402 King County Discretionary Assistance ISSUE Pursue a project to repair the approach slab seat on the west end of the Tukwila /Kent, jointly owned, 196th -200th Street Bridge under the 2014 Bridge Inspection Program, using the King County Discretionary Work Program. BACKGROUND The approach slab seat on the west end of the 196th -200th Street Bridge has sustained damage due to slab foundation fill settlement and resulting slab movement. The west end sidewalks approaching the bridge have also sustained damage due to pressure from the approach slab movement. DISCUSSION The approach slab fill settlement has been recorded on the routine bridge inspection report for a number of inspection cycles. Settlement has allowed the slab to rotate at the connection to the west bridge abutment causing concrete spalling and a bump at the bridge approach. The movement caused buckling of the sidewalk on the southwest corner of the bridge and was reported to Public Works on May 29, 2014. The settlement has reached the point where a repair is necessary for public safety and to protect the bridge from further damage. The King County Bridge Structural Engineer has inspected the bridge and determined that no restrictions are necessary as we pursue the repair project. FISCAL IMPACT This project is in the early stages of development and repair options are being determined and estimates prepared. The cost of the work is expected to fall within the budget of the 2014 Bridge Inspection Program. Updates to the committee will be presented as the information becomes available. RECOMMENDATION Information only. Attachments: Vicinity Map Bridge Inspection Report W:1PW Eng1PROJECTSW- RW & RS Projects\Bridge Inspection Programs\Bridge Inspections 2014 (91410402)1196th_200th Bridgellnfo Memo King Co Discretionary 196th - 200th Bridge - sb.docx 1 N Project Site 196TH — 200TH Street Bridge VICINITY MAP rTh Project Location ...►r ai, ss ;i 'v ook i •, +eo ec li ■11), I 'mai N 1 1* { .1► Illit +o T keno P ,,„/ /yf� illY� ,.. ,, I Q S ai n s,sos' I N Project Site 196TH — 200TH Street Bridge VICINITY MAP 196th -200th Street Bridge — Federal Structure Identifier 8712100 Inspection on June 2, 2014 by Tukwila Public Works, Grant Griffin and Scott Moore. Tukwila Road Maintenance requested an engineering review of the situation on the west end of the 196th- 200th Street Bridge that had caused the sidewalk to buckle on the Southwest approach. Review of the bridge revealed an ongoing problem of roadway fill settlement causing unanticipated movement of the west approach slab. This movement has caused damage to the approach slab seat and a bump at the slab bridge transition. Further investigation and analysis of the bridge plans indicate that no traffic restrictions are necessary but that a repair project is warranted to prevent further damage. The King County Bridge Structural Engineer has inspected the damage and is in concurrence with this assessment. See detailed photos of the damage below: 3 1- Settlement top of traffic barrier above NW corner abutment — approach slab interface. 4 2- Void behind West Abutment wall Spalling Concrete where slab connection is failing. Construction falsework is still in place. Void is approx. 10 feet deep or more. Reinforced fill on roadway side is supporting approx. two - thirds of the slab but is able to rotate causing spalling of the outside edge of the approach slab seat. No movement visible with traffic loads. Settlement is happening for the entire width of the bridge. 5 3- Settlement of slab on SW corner. Barrier with Fractured Fin finish visible. Initial settlement marked to track additional settlement. Void and falsework to left is same location as picture No.2 above. 6 4- View of void on NW corner. Slab settlement and falsework visible. Abutment wall column at left. 7 5- Slab settlement on NW Corner. Location above void shown in photo No.3 8