Structural response of masonry, reinforced concrete, and historical structures during the 10 August 2025 Sındırgı–Balıkesir earthquake (Mw 6.1)

On 10 August 2025, a moment magnitude Mw 6.1 earthquake struck the Sındırgı–Balıkesir region in western Türkiye. This study evaluates the seismic response of masonry, reinforced concrete (RC), and historical structures by combining recorded ground motions with detailed field observations. The earthquake produced strong short-period accelerations that mainly affected low- and mid-rise buildings. Masonry structures showed typical failure mechanisms such as out-of-plane wall collapses, corner cracks, and separation between wall layers caused by weak connections and low mortar strength. RC buildings exhibited shear damage at beam–column joints, soft-story mechanisms, and widespread cracking and detachment of infill walls. In contrast, several historical stone mosques and arch bridges experienced no visible structural damage. Their good performance is attributed to high-quality stone masonry, effective interlocking of structural elements, and favorable geometric proportions. Overall, the findings demonstrate that even a moderate-magnitude earthquake can cause significant structural damage when buildings have material deficiencies, construction faults, or inadequate seismic detailing. The results highlight the need for improved construction practices and targeted seismic risk-reduction strategies in the region.