Earthquake loss estimation due to damage to residential masonry buildings during scenario earthquakes in Nepal

Abstract

Historical records indicate that large-magnitude earthquakes have frequently impacted Nepal, leading to widespread destruction and significant loss of life. This study quantifies potential earthquake losses for residential masonry structures by analyzing damage data from the 2015 Gorkha earthquake across 31 affected districts. The residential buildings in the study area are categorized into seven typologies based on construction materials and the number of stories. Damage states were classified into five grades using the European Macroseismic Scale (EMS-98). Based on these classifications, empirical fragility curves were developed. These curves, integrated with exposure, consequence, vulnerability, and fault rupture models, served as the foundation for a loss estimation analysis. We examined three distinct earthquake scenarios– two historical and one hypothetical - that are representative of seismic activity in central, eastern, and western Nepal. Although post-2015 Gorkha earthquake reconstruction efforts resulted in approximately 1,000,000 seismically compliant residential buildings, an estimated 814,690 pre-existing masonry buildings remain highly vulnerable due to their noncompliance with seismic provisions. This study provides municipality-level economic loss estimations, as well as damage distributions for residential masonry buildings, for three scenarios, marking the first time this has been done in the study area.