METHOD FOR CALCULATING DISTURBED THICKNESS OF SLIDE ZONE IN ROCK SLOPE WITH TWO-LAYER STRUCTURE

It is very difficult to calculate the disturbed thickness of slide zone in rock slopes with two-layer structure, although stability analysis of the rock slopes can be easily carried out. According to the theory of energy method, the formula of safety factor with meaning of upper bound solution is deduced in the paper. Furthermore, the formula of disturbed thickness is also derived when both the external work done by self weight of the slope and internal energy dissipation caused by slide zone are all taken into consideration. On the basis of analyzing a typical case, the paper puts forward a new concept of disturbed zonage about slide zone, and divides the disturbed thickness into five zones according to the degree of disturbance. They are the intensely, strongly, moderately , weakly and slightly disturbed zones. The depth range of reinforcing treatment for a two-layered rock slope should exceed the bottom of the slightly disturbed zone.