Evaluation of the Van Thrust Fault Buffer Zone within the Framework of the Provincial Level Disaster Risk Reduction Plan (IRAP); Van Bindirme Fayı Tampon Zonunun İl Afet Risk Azaltma Planı (İRAP) Çerçevesinde Değerlendirilmesi

Abstract

Within the scope of the Provincial Level Disaster Risk Reduction Plan (IRAP) carried out by the Disaster and Emergency Management Presidency (AFAD) in provinces with earthquake probability, the risk map of the cities has been started to be prepared. One of the priority titles of risk studies is determining the buffer zones of faults. The deformation and risk caused by the fault in the settlement area cause loss of area and value on the surface. In order to prevent loss of life and property during a possible earthquake, great importance to determine the buffer zone correctly. In this study, the engineering properties of the Pleistocene-Holocene clay deposits in the Van/ Bardakçı region, which consists of old lake and stream sediments located in the east of Lake Van, and how the thrust fault cutting these sediments affects the soils properties was investigated. The characteristics of the soils were determined on the clay samples taken from both the hanging and foot walls by drillings along the Van Fault which caused the 23 October 2011 (Mw = 7.1) Van earthquake. In the field, Standard Penetration Test (SPT) and Menard Pressiometer Test (MPT) were performed. At the same time, disturbed and undisturbed (UD) soil samples were taken from the clay deposits and their physical and mechanical properties were determined in the laboratory. When the results were evaluated, it has been determined that the soil properties of the hanging wall show lower strength properties than the footwall in the zone near to the fault. In disaster risk evaluations, it was concluded that the buffer zone on the hanging wall should be wider than on the foot wall in thrust fault zones. © 2025 Elsevier B.V., All rights reserved.