Mexico sits in one of the world’s worst seismic zones, and when we started working on the structural design of the Torre Mayor in Mexico City, it was less than a decade after the 1985 earthquake. Measuring 8.1 on the Richter scale, it wreaked devastation throughout the region and caused the deaths of at least 10,000 people.
“It was always at the back of our minds that we needed a new milestone in technology,” says Dr Ahmad Rahimian, Director of Building Structures at WSP in the USA. His innovative solution, for which he holds a US patent, used military technologies that had been declassified in the 1980s. “We came up with a system similar to the shock absorbers in a car,” he explains. “They are spread throughout the building so they act like the muscles on a skeleton. Many people questioned whether it would work, but testing showed it was a better solution than many available at the time and even currently.”
Completed in 2003, Torre Mayor remains one of Mexico’s tallest buildings at 55 storeys. But there have been several significant earthquakes since. “One day the client called me up and he said, ‘Ahmad, we had an earthquake last night that was 7.6 on the Richter scale. There were 200 people in the building – we only found out when people started receiving calls from their spouses anxiously asking if we were all right. We didn’t feel it at all.”