Russian scientists conducted a large-scale analysis of the causes of the collapse of buildings in Turkey after the earthquake

Russian scientists, with the participation of specialists from Kazakhstan, conducted a large-scale study that allowed them to determine the complex of causes of massive building collapses in Turkey after the earthquake on February 6, 2023. Rustam Akbiev, Ph.D., Head of the Department of Integrated Urban Planning Security of the Federal State Budgetary Institution "TSNIIP of the Ministry of Construction of the Russian Federation", Chairman of the Board of the Eurasian SEISMO Association, shared the results at a joint webinar with the International Forum and the 100+ TechnoBuild Exhibition.

According to him, the authors have carried out a significant amount of expert and analytical research, analyzed the mechanism of occurrence and models of a series of earthquakes, the seismotectonic situation in the region before and after, as well as the consequences of the largest earthquakes in the recent history of Turkey. 

For example, the building code in Turkey appeared for the first time after the earthquake in Erzincan (1939), and in 1999 it was seriously revised after the Izmit earthquake. At that time, 50-70% of the buildings were destroyed or severely damaged. This was followed again by a significant revision of the norms (the latest changes in 2020) and the adoption of a National Strategy with an Action Plan for Earthquake Mitigation (2012-2023).  However, experience has shown that its provisions regarding existing buildings have not always been faithfully observed. Nevertheless, the efforts were not in vain – most of the buildings destroyed in 2023 were built according to the old standards. 

"The scale and nature of the destruction, as well as the causes of its origin, are generally typical of similar events," the report says. – They are caused by an underestimation of the specifics of seismic activity and the danger of the region; shortcomings, imperfections and violations of standards for earthquake-resistant construction; unjustified savings in materials, poor quality of construction; lack of necessary responsibility of participants in urban development; lack of control over the condition of buildings during operation. All this manifested itself in the most unfavorable form during the Turkish earthquake."

A big role was played by the fact that builders in Turkey often do not comply with the requirements for the regularity of buildings in terms of plan and height, which in real life was aggravated by unjustified alterations /redevelopments.

A significant number of destroyed buildings were built in monolithic construction conditions according to a non-rigid structural scheme, including many of them with "flexible lower floors", with floors of minimal thickness and insufficient reinforcement, which due to the lack of the required number of vertical diaphragms (walls and connections) They could not ensure the spatial nature of the work of the structures and their required earthquake resistance.

The world experience in analyzing the effects of strong and destructive earthquakes was not taken into account, which shows that buildings with a rigid structural system should be built on weak soils, and flexible ones on hard soils.

The regulatory and regulatory documents of Turkey did not take into account the possibility of increased seismic impacts, their nature (significant vertical component, high-frequency spectrum of the "impact" type) at construction sites, territories of nearby cities and settlements to the focal zones.

An important factor in the increase in the scale of damage in the epicentral zone (up to 50 km from the source) during the Turkish earthquake was the recurrence of seismic tremors, which led to the destruction of "low-cycle fatigue" and the operation of structural system elements in an area that is not taken into account by standards in any country, including Turkey.

The report containing the rationale and conclusions of the research can be found on the 100+ TechnoBuild YouTube channel. In addition, the topic of earthquake resistance of buildings will be discussed at 100+ in Yekaterinburg from October 3-6.