Rock Slope Stability under Temperature Fluctuations

Abstract

Air temperature fluctuations cause intermittent shrinkage and expansion of rock blocks close to the surface. These cyclic deformations can bring cumulative and irreversible displacement of blocks down rock slopes, creating potentially dangerous conditions. This chapter presents examples from stations monitoring various slopes and natural cliffs that illustrate this phenomenon. The chapter will also present the results of a laboratory experiment performed on a block system that simulates the typical geological structure of a slope in a stratified and cracked rock mass. Inside a tensile crack, a prismatic rock block serves as a wedge capable of accelerating the cumulative displacement. The results obtained from the laboratory measurements serve as a basis for calibrating analytical and numerical 3D models of the problem. The results of the laboratory experiment and the numerical models clearly show that the wedge is of great importance in accelerating the rate of movement of the blocks on the slope. Further numerical analysis performed on blocks on the slopes of Mount Masada shows that temperature changes alone could explain the blocks’ detachment from the slope.