WHAT HAVE BEEN ACCOMPLISHED:

JMEC has been structural consultant for the $26 million Concord Avenue Interchange Improvement project for SR242 in the Contra Costa County for the Measure C program.  The improvements included widening three bridges, constructing a new off-ramp structure, 8,000-ft of retaining walls and MSE walls and 8,000-ft of soundwalls, including special retaining walls underneath the existing bridge and along freeway off-ramp.

The 160-ft span Concord Off-Ramp Overhead was constructed of cast-in-place precast box girder over a railroad right-of-way.   Due to the close proximity of the fault line, a single span with extra seat widths have been used to allow for large seismic displacement.  MSE walls were used at the bridge approach to reduce structure costs and to minimize earthwork.   Curtain walls were added to the abutment footings to reduce foundation displacement without additional piles.

JMEC has participated in Type Selection in the preliminary design phase, and  provided construction design support services.

Schedule:  Construction was completed in 1997