The HOV connector was constructed in the median of the freeway, and required 26’ high retaining walls. Traditional cantilever retaining walls could not be used due to their construction footprint, so MSE walls were considered. However, due to poor soil in the area, the weight of the fill would impact the existing roadway. Instead, TRC used an innovative approach which incorporates lightweight fill and precast panels for the structure approach.
Because the structures were designed to accommodate the ultimate future widening, it resulted in longer structure spans and eliminated the possibility of using multiple-span structures. This particularly impacted the Seal Beach Boulevard Bridge which was originally designed as a 5-span bridge, but had to be redesigned as a 2-span bridge with a long span of 254’. This span length in turn required a 10’-6” deep prestressed box girder which resulted in high prestressing forces.
Maintaining all freeway lanes for the existing traffic was crucial during construction, so extensive stakeholder coordination was required, including interface with OCTA, Caltrans, and seven affected cities.
Design for the project was initiated in October 2007 using an accelerated design schedule. The design effort encompassed 38 engineering reports and over 1,850 plan sheets. Construction will begin in June 2010 and is anticipated to last four years.
Please visit the OCTA Website for more information.