Experimental investigation of a catastrophic landslide in northern Pakistan

The territory of Azad Jammu and Kashmir (AJK) is vulnerable to different natural hazards because of its proximity to a geo-dynamically active zone and its tropical and monsoonal climatic pattern. Both factors operate in various combinations and result in the occurrence of disasters generated by natural hazards like floods, earthquakes, and landslides at different intervals. There are numerous landslides in the study area, out of which the Donga Kass landslide has been selected for study due to its ongoing activity which poses a significant risk to the nearby community and infrastructure. Therefore, assessment of two possible triggering factors (i.e., earthquake and rainfall) for this landslide was conducted through the laboratory testing using the DPRI-5 Ring shear simulator. Undrained cyclic loading tests were performed to simulate the dynamic loading and earthquake-induced landslides, while pore pressure control tests simulated the rise of groundwater level during rainfall for rainfall-induced landslides. Based on the laboratory test results, a critical seismic acceleration and a critical pore pressure ratio are suggested for Donga Kass landslide. Using these values and combining with rainfall data and monitored pore water pressure in bore holes, early warning system can be activated to reduce any potential landslide risk in the future.