Why most countries don’t have enough earthquake-resilient buildings
“We cannot design buildings to be earthquake-proof. We make them earthquake-resistant. Even if you follow the standards and codes, there is always a probability of failure and collapse, but that probability is a low probability,” Sasani says. “If buildings were designed based on the code, would some of them collapse? Yes. Would this many [buildings] have collapsed in Turkey and Syria? The answer is no.”
Syria first included earthquake safety measures in its building codes in 1995, and updated them again in 2013. But the country is in the midst of a 12-year civil war, and bombing from the Assad regime likely made structures more vulnerable to collapse during the earthquake, says Bilal Hamad, an engineering professor at the American University of Beirut and a former mayor of Beirut. As a comparison, some of his students studied how the 2020 Port of Beirut explosion, where large quantities of ammonium nitrate that had been idling for several years in the port suddenly combusted, compared to the power of an earthquake.
Sasani says the majority of countries use US building codes, but it takes some time for the rules to travel across land and sea, meaning the date they actually adopted the code could be well past the 1970s. For example, Hamad says that Lebanon didn’t require any earthquake safety in building until 2005. And it took another seven years, until 2012, for the government to require builders to hire technical offices to ensure the buildings were built up to code. In the earthquake’s aftermath, Turkey’s president claimed that 98 percent of the buildings that collapsed were built before 1999, although experts have cast doubt on the statistic, saying it’s been used to divert blame from his construction amnesties policy.
It also doesn’t cost very much to make future buildings earthquake safe, explains Karim Najjar, an architecture professor at the American University of Beirut, who researches climate-responsive design strategies. He says adding additional beams and columns to strengthen a building’s infrastructure is usually only a fraction of the total design. “These measures make 5 to 10 percent of the costs for the structures,” Najjar writes in an email to PopSci. “Often cement is reduced in the concrete for maximizing profits,” which can make the building less strong, and therefore, less earthquake-resilient.