Cefali & Associates, Inc. Consulting Structural Engineers, Los Angles, CA © 2019. All Rights Reserved

Wilshire Grand Hotel

The New Wilshire Grand tower replaced the existing Wilshire Grand Hotel in the heart of Downtown Los Angeles.  The 1952 structure had a four level basement of a different footprint than that of the new building.  Cefali detailed the earth shoring installation to coincide with the phased demolition of the existing basement walls and decks.  Cefali designed a sled on which the tieback drilling machine could sit atop the old concrete decks to install tiebacks as the demolition progressed.  The excavation was design to accommodate the four subterranean parking levels and tower mat foundation extending 98 feet below Wilshire Boulevard.  The shoring was also highly coordinated with Revit and Navisworks models, especially beneath the 7th Street Surface where two Metro Redline Line tunnels were as closes as 5 feet from the soldier piles and 10 feet from the tiebacks.  At and below the level of the tunnels the excavation was supported by preloaded rakers.  The tiebacks, rakers, soldier piles, and tunnels were highly instrumented to monitor the excavation movement in real time.  Construction of the mat foundation earned a Guinness World Record for longest continuous pour of concrete.  All that concrete was poured in a pit surrounded by Cefali shoring using concrete boom pumps sitting atop the perimeter excavation.  The New Wilshire Grand tower has since become the tallest building west of the Mississippi River.