San Gabriel Trench Grade Separation Project
Owner: Alameda Corridor-East
Location: San Gabriel, CA
Construction Cost: $280 Million

Project Features:

  • Largest Grade separation Project in the ACE Program

  • Staged Construction with Railroad Shoofly and the Traffic Detours

  • Environmentally Sensitive Area

  • Protection of historic site, San Gabriel Mission and other structures

  • Precast Prestressed Bridge Construction

  • Secant Pile Wall Construction Method

  • Numerous utility relocations
As the structures lead firm for the consultant team administering and inspecting the project for ACE, Athalye provides constructability review for the structures of the project to clarify the project for bidders and assures a smoother project execution. Athalye also performs construction engineering and inspection for all structures.
This 2.2-mile San Gabriel Trench grade separation project has a 1.4-mile depressed section of the Union Pacific Railroad (UPRR) tracks into a concrete trench through the City of San Gabriel with bridge overhead structures (Precast Prestressed I-Girders) at Ramona Street, Mission Road, Del Mar Avenue and San Gabriel Boulevard. The trench walls consist of secant piles with a cast-in-place facing. Retaining walls are constructed using tie-backs and push-pull steel piles that are installed without vibration and with minimal noise with respect to the close proximity of the San Gabriel Mission and other historic structures.