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I-405 Improvement Project

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I-405 Improvement Project

Legacy Foundations was responsible for 13 large-diameter drilled shafts and 741 26-inch sound wall CIDHs. The 405-73 Connector includes 12-foot diameter drilled shafts along one of the busiest sections of freeway in Southern California. The shafts require a 13.5-foot diameter permanent casing, with an average length of 30 feet, to be installed as a predecessor to the 12-foot diameter CIDH. The deepest 12-foot diameter CIDH will reach 198 feet in depth. Crews will install temporary casing using a 3.6m oscillator, set 11-foot diameter rebar cages weighing close to 328,000 pounds, and tremie place over 800 cubic yards of concrete in each shaft—all while maintaining live traffic in both directions of the work zone. The project includes widening and replacing several structures, as well as the replacement of soundwalls, ramps, grading, drainage systems, and utilities along 16 miles of the 405 Freeway from State Route 73 to Interstate 605.

Project Details

Location:Orange County, CA
Amount: $20M
Delivery Method:Design-Build-Operate-Manage
Client Name:Orange County Transportation Authority (OCTA)
Duration: 2019-2022