ACE San Gabriel Trench

San Gabriel, CA

The 2.2 mile San Gabriel Trench grade separation project consisted of the lowering of a 1.4 mile section of the Union Pacific Railroad track in a trench through the City of San Gabriel. Twining provided quality control services for this $498.5 million project. Twining’s Vice President of Applied Engineering, Dr. Boris Stein, provided innovative green and economical concrete mix designs, and was available throughout construction to troubleshoot any unforeseen materials issues. Twining provided QC management and on-site materials testing. Our services included field sampling and testing services during concrete placement, HMA QC placement inspection testing, special inspection testing, and laboratory testing.  Twining also provided a construction quality control manager to oversee and implement the contractor’s quality control program, as well as provide document control and process in accordance with the project’s general provisions. Our firm also supplied an on-site concrete curing fog room.

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