BART Warm Springs Extension Project, Alameda County, CA

The Warm Springs Extension (WSX) is a 5.4-mile extension of the existing Fremont line to a new Warm Springs Station. The WSX involves extending BART beyond the Fremont Station into southern Alameda County near the county line. The goal of the WSX is to increase transit trips, particularly those destined for, originating in, or passing through southern Alameda County. PARIKH is the geotechnical engineer-of-record (EOR) for the Line, Track, Station & Systems (LTSS) contract.

PARIKH conducted Phase I Initial Site Assessment (ISA) for environmental document and provided full geotechnical service for the LTSS contract, a design-build program. The project elements consist of the followings:

• Trackways,
• Mechanically stabilized embankment (MSE) walls,
• Bridge structures at Walnut Ave and Grimmer Blvd, and
• BART Warm Springs Station.
• Challenges
• The crossing at Walnut Ave is located on top of the Hayward Fault. The potential fault displacement is the main design challenges for this structure. The bridge abutments consisted of MSE walls supporting shallow foundations, and the MSE walls were specially designed to account for fault displacement.