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Project Title & Location
I-5 HOV - South 48th Street to Pacific Avenue, Tacoma
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Project Description
Improves safety on I-5, from 38th Street to I-705 by adding a collector-distributor lane for safer merges on and off the freeway.
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Recent Progress
The Yakima & Delin bridge columns and abutments are complete, and the steel box girders are set to their final positions. The Northbound and Southbound I-5 traffic lanes have been reverted back to the permanent configuration. Falsework is being installed on these bridges in preparation for deck placement.
Pedestrian bridge demolition is complete.
Work is complete on the artistic noise barrier walls along Northbound I-5 from 48th St vicinity to 38th St vicinity (SNB wall) and along the Jenny Reed School (JNB wall). The NW wall is 99% complete. Work is complete on the NWSA retaining wall and the HRW keystone modular block wall. Approximately 90% of the select backfill was placed against the temporary portion of the GW wall. Crews are starting the final phase of artistic fascia on the GW wall from Yakima Ave. to the end of the project.
Sign bridge foundations, cast-in-place barrier construction, and electrical work are 50% complete. Drainage work is 90% complete.
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Design Construction Impacts
As reported in December 2006 QPR, the finished slope at the end of the new NW wall became unstable during the November 2006 rainstorm. The project office discovered that the slope condition above the adjacent property and building is not globally stable, meaning water runoff and mudslide problems will persist. The permanent solution is expensive and interim solutions do not offer a satisfactory level of safety against mudslides and discharges to the adjacent property. WSDOT is looking into the purchase of adjacent land and building to allow for slope flattening and management of the slope's water runoff.
New sign bridge #7 was added to the contract to provide an advance replacement of an existing sign bridge to take advantage of current traffic control and to avoid the cost of retrofitting the current structure.
A portion of the City of Tacoma waterline relocation work was added to the contract. This work is located north of Delin bridge. This work created conflicts within the schedule which required the contractor to reconfigure work operations in the area.
The project encountered a differing site condition during Delin Bridge Pier 2 shaft excavation. Soil conditions differed from those shown in the contract and required extra effort to complete shaft installation.
The project office and contractor are working through the impacts resulting from additional stabilization of the old Yakima Bridge during the demolition phase.
The project office and contractor are working closely with Holy Rosary Church in monitoring cracks in some masonary columns and walls.
The project office is monitoring potential utility conflicts with the remaining structure and drainage work.
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Environmental Impacts / Compliance
Noise barrier walls are being constructed to minimize the traffic noise on adjacent residences and schools.
Storm water detention ponds are constructed for use as part of the contractor’s temporary erosion control measures. They will later be modified for permanent water quantity and quality treatment to accommodate the widened roadway.
To ensure compliance with all permits and regulations, on-site meetings are conducted with the Department of Ecology and with the City of Tacoma as needed. We expect one final meeting this coming winter to review final stabilization.
On 7/19/07, during rainfall, discharge was tested in 2 areas of the project - M St. and S. Tacoma Way (SE and SW Quadrants). Both tests exceeded the allowable amount of turbidity. BMPs (Silt fence and catch basin insert) were in place prior to turbid discharge at the upstream and construction entrance. The cause of the turbid discharge is from broken sandbags and soil build up along the curb and gutters from vehicles exiting the jobsite.
Ecology Field Report dated July 23, 2007 indicated a violation of permit condition S3 for compliance with standards (failure to use all necessary BMP's to keep from discharging turbid water). Compliance issues/recommendations are as follows:
1) Repair/replace concrete washout area at panel yard.
2) Provide proper flow measures for the slope above the panel yard and M Street to include track walking
the slope, seeding, and jute matting application or plastic cover.
3) Clean debris at the surface of the catch basin and replace the insert at South Tacoma Way.
4) Apply quarry spall for construction entrance at G Street and confine the parking of the construction
vehicles to stabilized areas.
5) Remove or repair channel in panel yard.
6) Cover off site stock pile with plastic or PAM.
7) Exceedance of the 250 NTU benchmark, was a result of too much discharge water from a pipe failure.
The Contractor addressed all compliance issues immediately.
On July 27, 2007 the project office reported to the Ecology inspector that the above issues were addressed and are now in compliance with Ecology's requirements. The project office staff are taking administrative steps to correct behavioral and operational breakdowns that led to the violation and to ensure the project fullfills the obligations of the environmental permits and agreements.
The project office and the contractor continue to work together to ensure the Best Management Practices (BMP's) are in place and maintained during construction.
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Impacts to Traffic
The previous traffic shifts of the Northbound and Southbound I-5 lanes for bridge-demolition work and girder setting work were successfully completed. The NB & SB lanes are now shifted back to the permanent configuration.
Motorists can expect periodic nighttime lane closures and/or ramp closures on northbound and southbound I-5 throughout the project limits.
Electronic message signs and highway advisory radios (HARs) will be deployed throughout the area to alert travelers about traffic conditions and lane closures during construction.
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