Numerical analysis of stability for an antidip stratified rock slope

As a specific instability of rock slope, an antidip stratified rock slope is different from the sliding one, and the failure mechanism has not been clarified yet. It is clear that the flexural toppling behavior is influenced by the geological structure significantly, and the numerical method based on continuum theory does not seem to work well. It is aimed to discuss the flexural toppling mechanism by using a universal distinct element code (UDEC), and to find out the critical parameters for the future large slope cutting. Firstly, a numerical analysis has been conducted to simulate the flexural toppling failure phenomenon, which happened in a construction site. Then, a series of numerical analyses have been carried out further in order to find out the critical geometrical parameters of the slope for flexural toppling prediction. A significant slip behavior is found between the blocks in the UDEC model; and typical flexural failure phenomenon is reproduced in the simulation. According to the numerical results, a thinner spacing of joints leads to a trend of flexural toppling in case of the same geometrical parameters of the dip angle and the gradient of the cutting slope. The toppling failure is related with an alternate relationship between the joint dip angle and the gradient of the cutting slope.