Damage to monumental masonry buildings in Hatay and Osmaniye following the 2023 Turkey earthquake sequence: The role of wall geometry, construction quality, and material properties

This article reports on the findings of an investigation on 29 historic stone masonry buildings located in the cities of Hatay and Osmaniye following the 2023 Turkey earthquake sequence. The earthquake couplet on 6 February (with moment magnitudes 7.8 and 7.5) and the following events (including another earthquake which occurred on 20 February with a moment magnitude of 6.3) resulted in significant damage to the buildings. To understand why, the examined buildings were assigned an EMS-98 damage level (ranging from 1 to 5) and descriptive response categories (masonry disaggregation, local mechanism, and global response). Overall damage statistics indicated that masonry disaggregation was common and coterminous with local mechanism response. Wall geometry and construction quality indices were then investigated to explore why these were the dominant damage mechanisms. Wall geometry indices highlighted insufficient amount of walls to resist the local seismic demands, particularly in the transverse (e.g. short) direction of buildings. This deficit promoted the formation of local mechanisms. Construction quality indices suggested that stone layouts did not enable interlocking and that the walls were prone to disaggregation. To further investigate the role of material properties on the observed damage, materials were characterized using three non-destructive testing techniques: ultrasonic pulse velocity (UPV) measurements to estimate the static elastic modulus of stones, Schmidt rebound hammer (SRH) tests to estimate the compressive strength of stones, and the mortar penetrometer (MP) tests to estimate the compressive strength of mortar. The measurements indicated poor mortar quality, which may have expedited failures. Using established correlations, various other important material parameters (e.g. mortar cohesion and homogenized masonry strength) are derived. It is envisioned that the damage observations and the material measurements in this article will inform detailed modeling efforts on the behavior of historic masonry buildings during the earthquakes.