Seismic vulnerability and sustainable retrofit strategies for traditional masonry heritage buildings in Oman

Traditional masonry buildings constitute an important part of Oman’s architectural heritage; however, their seismic performance has received limited systematic attention despite the country’s exposure to regional and local seismic hazards. This study presents a qualitative assessment of the structural characteristics, seismic vulnerability, and strengthening strategies for four representative traditional masonry typologies: mud brick (adobe), dry-Stone masonry, stone masonry with mud mortar, and coral-stone masonry with lime mortar. The assessment is based on field surveys, documentation of construction practices, and an indicator-based evaluation of architectural, structural, and foundation characteristics. The results are synthesized using radar charts to facilitate comparison of the relative vulnerability of the different typologies, while detailed schematic illustrations are used to document characteristic construction details, identify key structural deficiencies, and present practical strengthening strategies. The study shows that seismic vulnerability is primarily governed by inadequate wall connectivity, discontinuous load paths, weak diaphragm action, and poor structural integrity rather than construction material alone. Among the investigated typologies, dry-stone masonry exhibits the highest seismic vulnerability, followed by adobe masonry, whereas stone masonry in mud mortar buildings demonstrates comparatively improved performance and coral-stone masonry performs relatively better under the considered conditions. Based on the identified deficiencies, typology-specific strengthening measures are proposed with emphasis on improving structural continuity, diaphragm behaviour, and connection detailing while maintaining compatibility with traditional construction materials and heritage conservation principles. The proposed framework provides practical guidance for the seismic assessment, strengthening, and conservation of traditional masonry buildings in Oman and may serve as a useful reference for similar heritage structures in other earthquake-prone regions.