Investigating damaged and destroyed buildings after earthquake in Turkey
The devastating earthquakes that hit Turkey and Syria in February killed nearly 60,000 people, left millions homeless across more than a dozen cities, and caused billions of dollars in damage.
In an effort to understand why the earthquake caused a significant amount of destruction in Southern Turkey, Research Associate Professor Mustafa Mahamid, of civil, materials, and environmental engineering, visited the region to investigate damaged and collapsed buildings with a group of professors from the Middle East Technical University.“We focused our efforts on the city of Malatya where many buildings remained standing, but there was also a big number of buildings that collapsed,” Mahamid said. “The purpose was mainly to look at different types of buildings, collapses, damaged buildings, buildings with partial collapses, and to understand how the structures performed.”
During the trip, the professor had many different observations related to different locations. Some destruction was due to building issues that are the result of a greater system-wide problem with the building codes, construction, inspections, and the heavy use of building multi-story structures with reinforced concrete that were not designed or constructed properly and per the current standards.
Many of the old buildings designed before the building codes were updated to consider earthquake loads properly were destroyed or partially destroyed. The buildings that withstood the earthquake sustained minor damage. However, they were not safe and residents were not allowed to enter the buildings.
“With a strong earthquake like this there was shaking that caused cracking in the concrete, which reduced its stiffness making the structures weaker, and an aftershock could bring the building down,” Mahamid said.
The professor also noticed a myriad of problems related to improper construction, which included beams and columns without a proper detailing or buildings without proper lateral system.
“I looked closely at the joints between the columns and the beams and slabs, and it was obvious that what was used cannot handle an earthquake of this magnitude,” he said. “In the US, we have strict and clear requirements of what needs to be done at the beam-column and/or slab-column joints.”
Another observation was related to how the concrete was prepared when the buildings were constructed 40 or 50 years ago.
“If this concrete was made on site, who can go inspect the strength? Nobody,” he said. “The proportions of sand, aggregate, water, and cement is extremely important.”
In the Hatay Province, the destruction was intensified due to construction on poor soil, which typically amplifies the earthquake motion and the effect on the buildings was much stronger or different.
Many buildings are leaning to one side, and this is due to a known phenomenon called liquefaction. This is when the soil loses its strength, and it cannot support the building anymore and it will tip on an angle.
“The reason for this is the lack of a proper geotechnical engineering reports. There were no proper soil reports,” he said. “Typically, when there is a liquefiable soil, for seismic design, there should be site specific studies. This was clearly not the case in this area.”
Mahamid’s trip was several days and he expressed an interest in returning to the region to evaluate more buildings and bridges, and work with his peers and the government to help the people in the region.
“Many people fled these cities, and they are staying in refugee camps or with relatives in different cities. They lost everything, and they are anxious to know what happened to their homes,” Mahamid said.