Seismic bearing capacity of strip footing placed on a reinforced slope

The study estimates the lower bound values of the seismic bearing capacity of a strip footing placed on a reinforced cohesionless soil slope. The influence of slope angle, soil friction angle, horizontal seismic acceleration coefficient, depth of first reinforcement layer from the footing base and vertical spacing between two reinforcement layers was investigated. The effectiveness of using a reinforcement layer is expressed by an efficiency factor, which is the ratio of the bearing capacity factor for reinforced and unreinforced slopes. The bearing capacity increases by approximately 15 times for a few cases with a single layer reinforced slope. With the inclusion of another layer of reinforcement, this improvement is doubled. The influence of setback position of footing with respect to the slope edge is also investigated for a few representative slopes subjected to both static and seismic loading. Beyond a critical distance, the setback effect is negligible. Several design charts are presented. Stress contours are plotted to understand the failure mechanisms of unreinforced and reinforced slopes.