Slope Stability Analyses Subjected to Slide Head Toppling Failure Mechanisms

Numerous mixed failure mechanisms involving sliding of the blocks on the lower region and toppling of the blocks on the upper and intermediate regions of the slope continue to be experienced most sedimentary rock formation of dams, highways and open pit mine slopes all over the world. It is faulty to analyze the jointed rock slopes’ stability susceptible to a combination of modes of failure composed of sliding around the toe region and toppling of the rock blocks on the upper part of the slope based on the current analytical methods, which are based on assumption that the distribution of the potential failure surface bounding the potential mixed failure runs predictably from crest to toe of the slope. An Analytical model that takes into consideration the kinematic mechanism of the discontinuous rock slope with counter-tilted weak plane subjected to a combination of failure mechanisms involving sliding and toppling has hence been presented in this chapter. This involves an iterative process which involves the calculations of the dimensions of all the individual blocks as well as the forces acting on them, and then stability of every block is examined, starting at the uppermost block. The stability analysis of each block is determined. The blocks may either be stable, topple or slide. The overall slope is presumed to show instability if the lowermost block either slides or topple. The iterative process involves determinations of the nth block that topples or slides with and without counter-tilted weak plane respectively. The proposed analytical methods could curtail errors incurred due to the acceptance of the single weak plane for quantifying the failure mechanisms composed of slide head toppling rock slopes in physical situations with two planar weak planes.