2.7 Geometry slope:
Important parameters of slope geometry affecting the stability include height and angle of slope. The critical height of slope depends on shear strength, density and bearing capacity of the slope foundation. Slope stability generally decreases with increase in height of slope. As the slope height increases, the shear stress within toe of slope increases due to added weight. Shear stress is also related to the mass of the material and the slope angle. With increasing slope angle, the tangential stress increases which result in increase in shear stress thus reducing its stability (figure 9).

Figure 9 : Effect of slope angle on slope stability 