The Wilshire Grand Center tower replaced the existing Wilshire Grand Hotel in Downtown Los Angeles. The 1952 structure had a four-level basement with a different footprint than the new building.
Cefali coordinated the shoring installation with phased demolition of the existing basement walls and decks. A drilling sled allowed the tieback equipment to operate from the existing concrete decks as demolition progressed.
The excavation accommodated four subterranean parking levels and a tower mat foundation extending 98 feet below Wilshire Boulevard. The shoring used seven rows of tiebacks. Coordination used Revit and Navisworks models, especially beneath 7th Street where two Metro Red Line tunnels were as close as five feet from the soldier piles.
At and below the tunnel level, the excavation was supported by preloaded rakers. The tiebacks, rakers, soldier piles, and tunnels were instrumented to monitor excavation movement in real time.
Construction of the mat foundation earned a Guinness World Record for longest continuous pour of concrete, with concrete boom pumps sitting atop the perimeter excavation.
