Venezuela's Old Buildings Made It Vulnerable to Quakes

Older buildings, substandard construction, and geography left many neighborhoods in Venezuela vulnerable to strong earthquakes like the ones that struck the country this week. Engineers and other experts said the back-to-back earthquakes on Wednesday were among the most intense to hit the country in more than a century, leveling buildings and leaving more than 900 dead, with the number expected to rise. Videos and satellite imagery from the disaster zone reviewed by the AP reveal scores of multistory buildings had collapsed.

Microsoft's AI for Good Lab analyzed satellite imagery of Catia La Mar in La Guaira state, one of the hardest hit cities along the Caribbean coast. Using AI-based damage assessment models, Microsoft determined that about a third of the city's nearly 30,000 structures were damaged. Among the factors that left so many structures at risk: Some housing complexes in northern Venezuela were constructed quickly during recent oil booms, and builders may not have adhered to best practices that mitigate the risks of serious seismic activity, according to experts.

Engineers said that older housing erected in the 1950s and 1960s—before modern earthquake standards were adopted—may not have been retrofitted to survive such violent shaking. Plus, many buildings were constructed on geography and soft soils that compound the danger of the earthquakes, the experts said. Since the 1970s, engineers have known that concrete buildings are particularly susceptible to earthquakes and seek to reinforce new construction with steel. While many rich nations have forced property owners to retrofit or tear down dangerous buildings, many poorer or middle-income countries have lagged in enforcing upgrades as they battled more immediate woes.

Venezuelan government officials took steps following a deadly 1967 quake to update building codes, but it's unclear how many buildings were retrofitted to comply with those rules. At any rate, some of the newer buildings also appear to also have collapsed. "Something that leaves me perplexed is the fact that, among the collapsed buildings, more than one was recently designed and built in accordance with current standards," one civil engineer says. "We need to embark on a process not only of reconstruction, but also of reviewing the applicable standards, since something might have gone wrong within our engineering processes, too." More here.