1800 Avenue of the Stars Seismic Evaluation and Retrofit

Los Angeles, CA | 13 Stories

Built in 1963, 1800 Avenue of the Stars, located in the City of Los Angeles, is a 13-story office building with 3 1/2 subterranean levels totaling 302,500 square feet. Our structural scope included the seismic evaluation and retrofit of the existing building using the latest seismic design and retrofit criteria.

After careful evaluation of the seismic deficiencies for the existing building, a cost-effective retrofit program was proposed which included introduction of new concrete core shear walls at strategic locations to provide adequate stiffness and strength, as well as to provide continuous load path for seismic forces to the foundation with minimal impact on building configuration and occupancy.  The original lateral system of the tower consists of moment frame columns and beams. Existing elements were checked and integrated with the new lateral elements to satisfy the requirements of ASCE41-17 and City of Los Angeles Non-Ductile Concrete Ordinance.

The existing foundation system supporting the original structural system is deep foundation (driven piles). However, we worked with Geotech Engineer to come up with a shallow foundation retrofit solution for the new lateral system.     

Concrete shallow foundation (mini mats) was introduced to support the new shear walls.  New foundation solution proved to be cost effective as well as more favorable from constructability standpoint compared to deep foundation. The gravity load supporting system is composed of reinforced concrete, one-way waffle slabs at the first floor and below and 2-way concrete slabs at second floor and above supported on concrete columns