On 6 February 2023, a 7.8-degree earthquake was recorded with an epicenter in the city of Gaziantep in southern Turkey, very close to the Syrian border. The telluric movement had a depth of barely 10 km and has recorded more than 47,000 deaths between both countries.
Just 20 years ago, it was unimaginable to have the tools we have today to increase building´s safety. We currently have methodologies for calculation and design, higher quality construction materials and highly reliable regulations. So, why did so many buildings collapse in Turkey and Syria?
There are three elements that must be considered in these cases: seismic resistant design, quality control of construction and maintenance. According to versions of specialists in structural engineering, in Turkey and Syria there are failures in that three areas, which is a fatal combination.
Turkey has been hit by earthquakes on many occasions. The most recent events occurred in 1999 and 2011. The death toll on those occasions was lower than in 2023, but it was still catastrophic: 17,000 people lost their lives. Following these devastating events, Turkish researchers carried out various analyses on the behavior of the buildings and detected a series of deficiencies. Among the conclusions they reached, inappropriate design, unsupervised construction, low-quality materials, zero maintenance, and the presence of buildings on land with low support capacity can be highlighted.
According to Pelin Pinar Giritlioğlu, head of the Istanbul Chamber of Urban Planners of the Union of Chambers of Engineers and Architects of Turkey, for years, more than 75,000 buildings in the area affected by the earthquake in southern Turkey have received construction amnesties. That is, permissions to not comply with the most recent regulations. It is even known that not long before the recent catastrophe, the newer construction sites were awaiting parliamentary approval of a bill that would grant a new amnesty for them.
Mexico and Chile
“La Latino”, as Mexicans call the Latin American Tower in Mexico City, was inaugurated in 1956. This work is a landmark in world architecture for being the first anti-seismic skyscraper in the world, built in a city with extremely high seismic activity, on the swampy soil of an islet in Lake Texcoco. The building, 181 meters high and with 44 floors, contrasts with other works of the time that do not comply with seismic standards. In countries like Chile, tower engineering was used to shift towards seismic-resistant structures.
Because it was a large project for the time, the design and construction team decided to give the tower a flexible and light structure, which allows it to adapt to the movements of the most powerful earthquakes. “La Latino” has 361 concrete piles that, buried more than 30 meters deep, cross the muddy terrain until they find stable ground. It has 3,200 tons of structural steel and 75 seismic dampers. In addition, 39,000 cubic meters of reinforced concrete form the foundation of the tower, which expels the surrounding water thanks to an injection system and settles on the ground to the rhythm of the city, which sinks year after year.
Another key in its construction are three empty basements that function as a float, to imitate the physics of a ship on the waves of the sea. The tower sways on the ground with the same wave frequency as the seismic vibrations impinging on it. Thanks to its design and construction, it withstood the earthquakes of 1957, measuring 7.8 on the Richter scale, the 1985 earthquake, which is the most devastating on record, with a magnitude of 8.1 on the same scale, and the most recent, occurred in September 2017 and 2022.
Chile is the most seismic country on the planet, which is why it has fostered the foundations to also become one of the most advanced in terms of earthquake-resistant construction. Chilean engineers are clear that in this type of construction it is essential to have a reinforced concrete and steel structure like that of the “Torre Latino”, since these materials are flexible and resistant enough for the building to move and sway without collapsing.
The official Chilean standards, known as “Seismic Design of Buildings” and “Seismic Design of Industrial Structures and Facilities”, standardize the methodologies and procedures for anti-seismic construction of structures and facilities. To comply with this regulation, it is necessary to work with materials that guarantee seismic isolation. Education and research are also of paramount importance. For example, the Catholic University of Chile includes a company that has patented devices to reduce the impact of earthquakes, such as dissipating partitions, sliders with tie rods or self-centering rods, among other mechanisms.
Costa Rica and the planning importance
The Costa Rican Seismic Code includes a considerable amount of seismic resistant structural design components. This, added to the efforts of the Federated College of Engineers and Architects, and some ministries, represents a guarantee against large-scale earthquakes. These advances in human security are not tangible or visible to the same extent in countries of the region such as Nicaragua, Honduras, Guatemala or Mexico.
It is also important to recognize the relevance of managing the human factor in emergencies and disasters. For example, it is necessary to design and implement emergency preparedness and response plans that consider specific elements for training the occupants of a building, so that they know how to act in a possible crisis situation.
Simulation and drill programs must be established to anticipate potentially dangerous situations and to evaluate internal first response agencies, such as brigades and committees. At the community level, it is required that governments, municipalities and other political actors promote emergency preparedness through training support, so that the civilian population can generate their own preparedness and response plans.
Some institutions such as the Fire Department, the Red Cross, The Costa Rican National Emergency Commission and the Costa Rican Electricity Institute, among others, have made significant contributions in terms of regulation, inspection and training at the country level, leading, for example, the standardization of the Incident Command System as a response methodology against disasters.
Starting in 1999, there was a lot of apprenticeship in Turkey. Since then, they knew what to do and what not to build safe buildings. Unfortunately, this knowledge has not been put into practice, as has happened in Chile and Costa Rica. There was knowledge but no will. Consequently, during these days we have lamented the loss of thousands of lives and we have not talked so much about the old buildings but about those that were recently built, which also collapsed.