Due to heavy rain in the area, the slope wash/slope debris mass got saturated. Saturation of the porous material led to loss of cohesion and inter friction angle of slide mass causing sliding and differential settlement.

An Interim Report on Preliminary  Geological  Slope Stability Assessment of the Recent Disaster Affected Areas in Parts of Chamoli District, Uttarakhand by Bhupendra Singh, Bhupender Singh, Ajay Kumar and Arindam Roy, Senior Geologists, M-IV, NR GSI Dehr
UK_CHA_NH_ 015
Concrete retaining wall 25-30 m below road level, filling and compaction of sinking zone, breast wall at inner side.
Heavy precipitation resulting in saturation of overburden, toe cutting by Dhuli Ganga River.