Ground movement patterns and shallow foundation performance in Iskenderun coastline during the 2023 Kahramanmaras earthquake sequence

This study focuses on the field reconnaissance efforts for investigating ground deformation behavior and building foundation performance in Iskenderun. Many structures experienced significant damage or collapsed due to strong ground shaking in the coastal Iskenderun district of Hatay during the 2023 Kahramanmaras earthquake sequence. Many buildings were also impacted by ground failure due to liquefaction of deposits in the area. Preliminary information regarding the general subsurface profile and post-earthquake data collected during the reconnaissance was used to perform simplified liquefaction and lateral spreading analyses. The empirical methods provide first order estimations of settlements and lateral spreading but are not sufficient when the nature of the structure-soil-structure interaction and earthquake sequence is considered. Measurements of vertical displacements and building tilt, liquefaction manifestations, and structural and foundation parameters potentially affecting foundation settlements including foundation geometry, building contact pressure, and building elastic period were used to evaluate seismic response of the ground and the structures through empirical procedures. Most of the buildings exhibited poor to mediocre foundation performance due to liquefaction-prone subsurface profiles, especially on the coastline. Ongoing field and numerical research will reveal the cause of significant ground failure in the area as well as refined estimates for the seismic deformations.