Seismic vulnerability assessment of buildings in high-risk areas: A modified rapid visual screening approach in Pakistan

In this study, we evaluate the seismic vulnerability of buildings in Dir City, Khyber Pakhtunkhwa, Pakistan, using a modified rapid visual screening (RVS) approach. Based on the Building Code of Pakistan, Dir City falls within Seismic Zone III. The majority of the structures in the city are non-engineered and old, and were built by local masons; therefore, they could be vulnerable during a seismic event. One hundred randomly selected buildings, including residential, commercial, government, and religious buildings, were assessed in an RVS survey. The structural configuration of the surveyed buildings was diverse—unreinforced masonry, confined masonry, stone masonry, and reinforced concrete (RC) frames with unreinforced masonry (URM) infill. The materials and structural systems of each building were assessed using the RVS approach and employing a modified Federal Emergency Management Agency (FEMA) data collection form. Positive and negative score modifiers were used to assign and modify basic scores based on characteristics that increase or decrease seismic resistance in a building; low final scores indicate the need for further expert examination. The final scores were then mapped to damage grades representing potential vulnerability. Drawing on the study findings, suggestions for improving the earthquake resilience of Dir City are offered.