Site effects and associated structural damage analysis in Kathmandu Valley, Nepal

Nonlinear seismic site response analysis more accurately predicts structural damage patterns in Kathmandu Valley compared to equivalent-linear analysis, as demonstrated by the 2015 Mw7.8 Gorkha earthquake. The study found that nonlinear models better capture soil amplification and peak ground acceleration (PGA) variations, with PGA ranging from 0.17 to 0.46 g—closely matching observed damage scenarios. While equivalent-linear analysis underestimated amplification (2.3–3.8), nonlinear analysis revealed higher values (8.9–18.2), aligning with severe damage in three sites and minimal damage in two others. The research also exposed inaccuracies in the USGS PGA map for southern Kathmandu, contrasting with northern regions. Soil fundamental periods of 0.4–0.5 seconds were consistent across both methods, providing critical data for seismic demand analysis.

Gautam, D., Forte, G., & Rodrigues, H. (2016). Site effects and associated structural damage analysis in Kathmandu Valley, Nepal. Earthquakes and Structures, 10(5), 1013–1032. https://doi.org/10.12989/EAS.2016.10.5.1013