Geotechnical Variability of the Soils in the Kathmandu Valley, Nepal

The 2015 Gorkha earthquake caused considerable infrastructure damage and disruption. In the years that followed, the need emerged for planners to access hazard maps and better plan future developments and upgrades to existing infrastructure assets. In light of this, the ability to run stochastic simulations is important for scenario planning. When modelling geotechnical phenomena soil variability needs to be assessed. For stochastic modelling efforts, soil variability should be assessed statistically. There are two key geological units in the Kathmandu valley: the Gokarna and Kalimati formations. These valley sediments are highly variable but high-quality geotechnical data is scarce. To mitigate this data scarcity, a recently developed geotechnical database called SAFER/GEO-591 is used to determine the best fit probability density functions for key soil parameters in each formation relevant for geotechnical design and modelling efforts. The best-fit probability density functions can be used in modelling liquefaction potential, site, and foundation response for new and existing constructions in the valley.