Study on the Stability of Underground Grave Rock Mass Based on Block Theory

It is important for analysis the stability of rock mass to consider the mobile block. So The block theory that be instituted by including block mobile theorem, block kinematical analysis and sliding way of block is introduced. The stability analysis method of rock mass block is used to calculate the safty coeffinent of rock mass. Taking the powerhouse of La Xi-wa power station as example, the safety coeffinent of possible unstable blocks is calculated, result shows that the stability coefficient of downstream wall is F_s = 1.73-2.5, and the combinating way is constituted by fracture plane and air plane, the mainly unstable way of block in the wall is sliding down along some structure plane or the intersecting line of two groups structure plane. So the analyzing rock mass is relatively unstable, and some action must be done to strengthen the stability of rock mass.