Flat Roof Designed for Helipads

The Wilshire Grand Center is the first Los Angeles high-rise not required to have a flat roof for helicopter landings.

DTLA – It could be said that the middle of the new Wilshire Grand Center is somewhat common. It’s huge to be sure, but the 889 hotel rooms and 400,000 square feet of office space are similar to other offerings in Downtown Los Angeles.

What really makes the 73-story project stand out — in addition to being the tallest structure west of the Mississippi and a game-changer for the Downtown skyline — is what’s on top, and what’s on the bottom.

The Wilshire Grand is the first Los Angeles high-rise that doesn’t have a flat top for helicopter landings. At the base of the structure are seismic elements that would allow the building to withstand a magnitude 7.5 earthquake from one of the 29 active fault lines within 50 miles of the building.

The Wilshire Grand has an 18-foot-thick concrete foundation. That provides some of the greatest seismic support, according to Gerard Nieblas, president of Brandow & Johnston, one of the structural engineering firms that worked on the building.

The hotel rooms and office space are built around a concrete core (some elevators, staircases and other infrastructure are inside the core). That element provides stability for the tower’s outer walls. Wilshire Grand Week: From the Street to the Spire | Development | ladowntownnews.com