At 1136 Sixth St., just west of the heart of downtown Los Angeles stands The Mint, a nearly 100-year-old medical building that has been repurposed into luxury apartments.
Despite its age, it is very likely one of the safest buildings in downtown after a full seismic retrofit in 2016.
“What we did here was introduce a 16-inch concrete sheer wall that goes from the basement of the foundation to the roof of the structure,” explained Richard Chen, principal with Miyamoto International, Inc.
Inside those walls are seismic stirrups and ties which will allow the wall to dissipate energy in an earthquake.
This building was strong, but in earthquake engineering, there is a difference between strong and tough. As Chen explained, it needs to be tough so it can dissipate energy.
In 2015 the Los Angeles City Council passed the nation’s most sweeping seismic regulations.
Since then Miyamoto International has seen a steady increase in business. They’ve retrofitted iconic and crowded spots like the Griffith Observatory and the Hollywood Bowl.
But Chen says downtown LA is of concern because many of the towers were built with outdated technology.
There are a lot of high-rise buildings in downtown and most were constructed in the 1970s and ’80s. Those are all pre-Northridge earthquake and that’s when experts learned a lot about how these steel connections didn’t work well.
Chen says it’s unlikely the skyscrapers will collapse, but the chance the buildings will stay straight and be reusable after a big quake is very small.
While buildings like the brand new Wilshire Grand are built with the latest and safest earthquake technology, Chen says they’ve seen more and more developers come to them looking to retrofit older existing buildings wanting to make them safer and more profitable.
“If you think about it we’re running out of land to build new projects,” Chen said. “So developers are now looking at property that’s distressed or hasn’t been in use for decades and is trying to see if there are opportunities to turn them into better use buildings for a better investment.”