Stability Analysis of Surrounding Rocks of Underground Powerhouse in a Hydropower Station

The underground powerhouse of a hydropower station is a typical large-span and high side wall cavern group. The stability analysis of high side wall and the rock between caverns is key for cavern design. Based on the process of excavation and anchorage of underground caverns, FLAC3D numerical modeling technique is used to dynamically analyze the distribution rules and variation features of the second stress field, displacement field plastic zones in the rock masses surrounding the caverns before construction of anchorage support and the loads carried by the supporting structures. The computation result shows that the opening's lay out, construction sequence and support parameters are rational.