ABSTRACT

This paper deals with the dynamic slope stability analysis for rock slope excavation at pothead yard location for 720 MW Mangdechhu Hydroelectric project situated in Bhutan. The maximum depth of slope excavation is about 125 m. Dynamic analysis has been carried out at identified five cross sections using two dimensional discontinuum analysis by universal distinct element code (UDEC) software. The actual excavation geometrical profiles of slopes along with the rock mass including joints were simulated in the model. Slope stability measures in the form of rock anchors and shotcrete with welded wire mesh were provided as support system, the same has been included in the model and factor of safety (FOS) has been evaluated at each of these sections. Dynamic analysis is carried out at the five sections after the initial static state. The dynamic loading is given as a shear sinusoidal wave. The dynamic response of the slope has been analysed and stability of the slope has been assessed.