Probabilistic seismic liquefaction hazard assessment of Kathmandu valley, Nepal

Abstract

Earthquakes are frequent in the Himalayas and almost all moderate to strong earthquakes have caused enormous losses of lives and property in Kathmandu Valley, Nepal. Several historical earthquakes depicted that considerable loss was attributed to liquefaction induced failure in structures and infrastructures. Existing liquefaction studies have mostly used deterministic approach to obtain the factor of safety against liquefaction. Thus, to update the conventional deterministic liquefaction analysis results, this study performs probabilistic seismic liquefaction hazard assessment of Kathmandu valley considering wide range of earthquake magnitudes and four return periods: 73, 475, 2475, and 5000 years. Liquefaction probabilities for 88 locations across Kathmandu Valley are estimated and compared with the historical occurrence to validate the results. The liquefaction hazard maps for all four return periods are prepared for all the earthquake magnitudes for 1.5 m, 3 m, 4.5 m, and 6 m depths. The sum of findings highlights that the central valley, and eastern and western fringes have higher liquefaction probabilities than the other parts.