Effect of rock fragments on pore water pressure and slope stability at a hillslope

Abstract

This study investigates the effects of rock fragments on pore water pressure and safety factor of a slope. The study was conducted using computer software SEEP/W and SLOPE/W for a slope with and without rock fragment in order to get value for the pore water pressure and safety factor of the slope. The study also been carried out on the rock fragment characteristics such as position (top, middle and bottom) and size (large, medium and small) to find out the effects of rock fragments on hydrologic response and slope stability. The results show that the rock fragments obstruct water flow on the slope and increase the pore water pressure. However, higher pore water pressure can cause the slope to become less stable. These indicate that the safety factor for the slope with rock fragment is lower than slope without the rock fragment. The results also showed that pore water pressure and seepage flow response are affected by different position of the rock fragment. At a lower position of the rock fragments, the pore water pressure is the highest. Therefore, the safety factors are smaller compared to other rock positions. On the other hand, the results show that the pore water pressure and safety factor of the slope are less influenced by the size of rock fragments.