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 246-ft 4-span Solano Way Undercrossing was widened using reinforced concrete girders following Caltrans bridge widening policies and procedures.   The widening bridge was designed to resist the seismic loads from the existing structure.  Joint shear reinforcements were used to strengthen the footing and bent cap joints.

In the preliminary design, JMEC has participated in the Type Selection and seismic retrofit strategy determination.

JMEC provided services during construction including shop drawing review, field visits, review and respond to queries from contractors.  One of the retaining wall footing was redesigned to avoid unanticipated existing utility.

Special Issues:  Curtain walls have been added to the foundation to help mobilize the passive soil resistance and to reduce foundation displacement without additional piles. Special retaining walls have been used along NB off-ramp in lieu of tie-back walls.

Schedule:  Construction was completed in 1996