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Project Title & Location
Eastbound Off Ramp to Weyerhaeuser Way and Weyerhaeuser Way to SR167
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Project Description
This project adds a truck climbing lane to westbound SR 18 between SR 167 and Weyerhaeuser Way. The project will also modify Weyerhaeuser Way ramp terminals and add signal to westbound ramps.
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Recent Progress
The contractor has completed most of the drainage, grading and wall work on the Federal Way end of the project. Final illumination and paving remain. Work on bridge foundation and piers are complete. The contractor is working on bridge deck, and at the east end, wall installation.
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Design Construction Impacts
Discrepancies between actual ground elevations and surveyed information used for project design have required numerous design changes during construction. The Peasley Canyon Bridge east end pier and the retaining walls to the east were redesigned to compensate for these elevation changes. The two intermediate piers required an adjustment of the shafts to match existing elevations. The precast barrier on the shoulder of SR18 required revisions due to stability concerns. A temporary illumination system was added to southbound SR167 to westbound SR18 ramp.
The contractor has proposed three Cost Reduction Incentive Proposals (CRIP) that we have accepted. One was for widening the bridge superstructure from cast in place box girder to a precast girder structure. Two were for changes to wall structures to make them easier and more cost effective to construct.
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Environmental Impacts / Compliance
Early in construction we had difficulty meeting water quality discharge requirements. The contactor suggested use of a chitosan sand filter system. Though the chitosan filter performed well, it is still considered an experimental system by the Department of Ecology. Because of this, we stopped using the chitosan filter and returned to using more traditional temporary water pollution control items. We are meeting water quality standards.
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Impacts to Traffic
The roadway has no shoulders throughout the job. Traffic lanes were shifted in May 2004. Additional nighttime single lane closures will occur as needed. Final paving and re-striping of the road will occur in spring 2005.
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