Steps to Ensure the Wilshire Grand is Earthquake Ready

The Conco Companies have been in business for decades, and as such, have had the opportunity to provide concrete services on a broad range of commercial, educational, healthcare and public works projects as well as parking structures.  One very large and exciting project we are proud to be a part of is the Wilshire Grand Center, which when complete, will become the tallest building in the U.S. west of the Mississippi.  

The 73-story 1,100 foot skyscraper is located in Downtown Los Angeles and is right in the middle of a seismic hot zone with a fault less than a ½ mile away that has an estimated capacity for a 6.4 magnitude earthquake.  This means that even before construction began several steps had to be taken to ensure it was ready in the event of an earthquake. 

 

Much of the early work came in the form of the architectural and engineering design.  The Los Angeles-based architectural firm, A.C. Martin Partners, who prepared the current design and is overseeing the project designed the building with a garage and plaza that consists of five levels of 13-inch thick concrete floors.  This will work to “transfer lateral loads such as seismic activity or Santa Ana winds to the walls or frames” of the building.  

Another example of how the skyscraper was designed to protect it from seismic shaking is the construction of its core that consists of four-foot thick walls and contains steel-plate box columns filled with concrete.  The core will hold the building’s elevators and staircases.   Furthermore, an additional 10 columns are linked to the core.  These act as “structural shock absorbers to absorb the energy that an earthquake might produce.”

Before Conco’s historic, record setting continuous mat pour even took place in February 2014, the skyscraper’s design had been put through some of the most advanced and sophisticated earthquake modeling available.   After a series of numerous tests and studying damage from past earthquakes in Southern California, the engineers refined the size and depth of the foundation.   In addition they added devices called buckling-restrained braces.  These long steel bars are encased in steel boxes and filled with grout to allow the bars to compress or stretch when the building moves.

At The Conco Companies, we are one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products.  Our experience includes providing services for commercial, educational, parking and other construction development as well as public works projects.  We serve California, Washington State, Oregon, Colorado and Nevada.

Sources:la.curbed.com/archives/2014/02/how_the_wilshire_grand_will_stay_upright_in_a_major_earthquake.php