ABSTRACT
For performing the research, seven rock slopes along the margin of Ganjnameh-Shahrestaneh Road, Hamedan Province, western Iran, were selected, and the physical and mechanical properties of their rocks and discontinuities were determined. Rock slope stability analysis has been performed using kinematic and limit equilibrium methods so that safety factors for the rock slopes can be calculated. Also, sampling of filling materials and XRD tests have been done to identify the clay minerals in the filling materials. The lithologies of the studied rock slopes are granite, diorite, and hornfels. The presence of discontinuities and weakness planes with different orientations and clay minerals in filling materials of discontinuities are effective factors that cause plane, wedge, and toppling failures in the rock slopes. Clay minerals as filling materials of discontinuities in the studied rock slope facilitate their instability by two different methods. First, absorption of water by infilling clay minerals causes the friction angle of discontinuity surfaces that leads to plane and wedge failures to be reduced. Second, water absorption causes the swelling of clay infilling minerals that leads to toppling failure.
