I-880 Express Lane & Median Barrier Replacement Project,  Santa Clara/Alameda County, CA

Metropolitan Transportation Commission (MTC) and Caltrans were pursuing development of an integrated Bay Area express lane network to enhance mobility and afford greater user flexibility of the transportation system. The new express lane is approximately 25 miles long along I-880 from north of Route 237 Interchange to north of Hegenburger Road. The existing High Occupancy Vehicle (HOV) lanes were converted to express lanes in both northbound and southbound directions. The project elements included:

• Pavement widening at ‘Truck Scales’, south of Alvarado Niles Blvd. Overcrossing and Hacienda Avenue Overcrossing.
• A total of fifty-nine overhead sign structures supported on CIDH piles under both projects.
• Retaining walls (soil nail wall, semi-gravity walls, sub-horizontal ground anchor wall, and soldier pile walls) for the proposed widening near Hacienda Avenue Overcrossing.

Challenges

• Alluvial deposits with loose to medium dense sand are common at the project site, which contributed to caving in during the construction of the CIDH
• concrete piles. PARIKH recommended the use of permanent casings. PARIKH was able to reduce the pile lengths by verifying the pile capacities meets the design demands.
• PARIKH promptly responded to the queries from Caltrans regarding the CIDH pile anomalies to avoid delaying the construction.