Failures in structurally stable slopes in southern Hamrin mountain, East of Iraq

The engineering geological study of rock slopes in southern Hamrin Mountain, Sidoor area, East of Iraq revealed that in some failure sites the discontinuities within the rock masses constitute stable blocks which do not verify geometrically the conditions of any type of failure, and therefore, must be structurally stable. Nevertheless, toppling failures have occurred here because of the activity of differential weathering and / or erosion which consequently modified the state of rock masses below the slopes and redistributed the stresses within them leading to failure. This emphasizes the necessity not to rely absolutely on the structural setting in assessing the stability of rock slopes, but there might be other geological factors that either make the structural factors of secondary importance, or act in adverse manner to the effects of structural factors with time.