Post-2015 earthquake vulnerability of typical RC buildings in Kathmandu Valley

Continuous assessment of the existing conditions of the buildings and performance expectations for future earthquakes is quite crucial for a high-seismic-risk city like Kathmandu. This study aimed to understand the impact of the 2015 Gorkha earthquake on the reinforced concrete (RC) buildings in Kathmandu Valley. The primary objective of this research is to compare the performance of RC buildings in pre-2015 and post-2015 mainshock-aftershocks-damaged conditions. In a nonlinear model of typical RC representative buildings in Kathmandu, incremental dynamic analysis (IDA) was carried out using a real suite of ground motion records, and the Park-Ang damage index was used to classify the damage. Fragility curves were constructed using the probabilistic seismic demand model (PSDM) from the IDA analysis, and comparisons were made between pre 2015 conditions and post-2015 conditions. The findings indicate that the most recent buildings were not significantly harmed by the Gorkha earthquake, and the performance anticipated for future earthquakes reveals that the code principles for design-level earthquakes do not adequately concur with the performance expected. Additionally, the expected seismic performance of the buildings is shown for several future earthquake scenarios.