Seismic failure modes of masonry structures exposed to Kahramanmaraş earthquakes (Mw 7.7 and 7.6) on February 6, 2023

Abstract

In this study, the failure modes of masonry structures after the earthquakes (Mw 7.7 and 7.6) occurred in Kahramanmaraş on February 6, 2023 were investigated by fieldwork. Within the scope of the study, information of the building stock in Türkiye and the Middle East countries was given, and a literature regarding the major failure modes in masonry structures was mentioned. The characteristics of the ground acceleration and earthquake parameters measured during the earthquake were presented. Damage distributions in historic masonry structures and masonry dwellings were examined. In addition to the out-of-plane behavior which is the most common failure mechanism in masonry structures, the corner failure mechanism has been also observed in many masonry buildings. It has been determined that the corner failure mechanism is triggered by the combination of the in-plane and out-of-plane failure behaviors. In this manner, the observed damages were classified as in-plane, out-of-plane, and corner failures. It has been determined that damaged masonry structures are mostly out of use with out-of-plane and corner failure mechanisms. These two failure mechanisms were directly related to inadequate wall-roof and wall-floor connections, insufficient axial load, low material strength, poor workmanship, and the lack of engineering service. In-plane failure mechanisms are triggered by irregular door and window openings exceeding the limits given in the regulations. In addition, it has been revealed that many masonry buildings do not have adequate vertical and horizontal lintel band to increase the lateral seismic performance of the walls. In the last part of the study, the advantages and disadvantages of the strengthening methods that can be used in masonry structures with light and moderate damage were examined, and some suggestions were made.