Mapping the seismic safety of RC "template schools" in Nepal

Seismic risk assessment of a template school across Nepal is carried out to evaluate the suitability of a single design structure across an area with variable seismic hazard. Many non-governmental organisations (NGOs) use template designs for buildings as a method of reducing design costs; this results in a single seismic design used over a large area. Such an approach is particularly popular in Nepal as the government requires that all school designs obtain approval from the Department of Education. Probabilistic seismic hazard analysis (PSHA) studies have shown a varying seismic hazard across Nepal with the PGA a 475-year return event ranging from 0.05 g to 0.73 g. Pahar trust, a charity that builds schools in Nepal, provides the design of a reinforced concrete (RC) structure with masonry infills. Finite element (FE) models and fragility curves are developed with and without the masonry infill as to explore the effect of masonry infills on the seismic risk. The hazard and the fragility are then integrated to find the seismic risk of the template school across Nepal. The damage distribution is then evaluated for the template school under a 475-year and 2475-year earthquake. The probability of the school exceeding damage limitation (DL) and life safety (LS) has significant geographic variation, with a 475-year earthquake causing the school to exceed DL in most locations and a 2475-year return earthquake causing the school to exceed LS in the majority of locations. The structural contribution of infills brings the risk level below the threshold typically employed as reference in Europe.