Rescuers and volunteers conduct a search and rescue operation among the rubble of a collapsed building in Diyarbakir, Turkey, following a magnitude 7.8 earthquake on Monday. Ilyas Akengin/AFP via Getty Images hide caption
Rescuers and volunteers conduct a search and rescue operation among the rubble of a collapsed building in Diyarbakir, Turkey, following a magnitude 7.8 earthquake on Monday.
Structural engineer Jonathan Stewart The sight of thousands of buildings in southern Turkey and northern Syria in ruins came as no surprise after Monday’s deadly 7.8 earthquake and its many aftershocks.
“We’ve seen this before,” said Stewart, an engineering professor at the University of California, Los Angeles, who was part of an infrastructure assessment team sent to Turkey after the massive 1999 earthquake in northern Turkey.
Fast-forward to Monday, and the video of the devastation showed a “damn” – the sudden collapse of a high-rise building as bystanders fled for their lives.
This region is one of the most seismic in the world, as it is located at the junction of three tectonic plates. In addition to the 1999 earthquake that killed more than 17,000 people, Turkey was hit by a major earthquake in 2011 that killed hundreds of people.
This time the death toll has topped 5,400 in Turkey and more than 1,800 in neighboring Syria, where infrastructure is crumbling after years of civil war.
Survivors may be under the rubble in both countries, but it is estimated that more bodies may be found in Turkey in the coming days under the rubble of some 3,000 buildings destroyed by the earthquake.
Why did so many buildings collapse? Reinforced concrete is commonly used in Turkey for buildings over three stories high, Stewart said.
“Usually the columns and beams are concrete,” he said. “And then there’s a kind of masonry in those frames, and it falls apart very quickly when the shaking starts.”
Abby Liel, an engineer and professor at the University of Colorado at Boulder, said the assessment was in good agreement with what she saw in photographs of the devastation in Turkey.
Rescuers searched for casualties and survivors among the rubble of a collapsed building in Aleppo, Syria on Monday. AFP via Getty Images hide caption
Rescuers searched for injured and survivors among the rubble of a collapsed building in Aleppo, Syria, on Monday.
When designing an earthquake-resistant building, she says, you need to think about “deformability” and not about this fragile structure.
Keith Miyamoto, a disaster recovery expert preparing to travel to Turkey as part of a team of engineers, said building codes following the 1999 earthquake near Izmit were good, but many buildings predated those codes.
“Anything built before 2000 can be considered very dangerous,” he said. Also, even with the new building codes, enforcement is “not very reliable” so even some of the newest buildings don’t necessarily meet the standards.
Alanna Simpson, senior disaster risk management specialist at the World Bank in Bucharest, said the amount of steel and type of concrete in a building can distinguish buildings still in the quake from ruins.
“Steel buildings actually respond quite well to earthquakes because they are quite flexible,” she said. “So the more steel there is in a building, the more responsive it is.”
Turkey’s building codes were updated again in 2018, she said. But the country’s “legacy” remains fragile, like much of the rest of the world, she said. “This is a global problem.”
It’s also important to note that Monday’s quake was so strong and shallow that “an earthquake like this would happen almost anywhere in the world and you would see serious damage to old structures,” Simpson said.
As for rebuilding safer buildings, “recovering from a tragedy of this magnitude is taking much longer than anyone would have hoped,” she said. “It’s expensive and requires a lot of coordination and outreach.”