Stability analysis of slope with water flow by strength reduction method

Abstract

Rainfall is one of the most critical factors with regard to slope instability. In this paper, the effect of seepage flow on slope stability is investigated by means of a strength reduction method. It is demonstrated that the factor of safety (FOS) for a sandy soil slope is influenced by seepage flow more than other types of soil. If the pore pressure is generated by the use of a piezometric line, the FOS is smaller than that generated by seepage flow analysis. The difference is small for clayey soil slopes but is larger and more noticeable for sandy soil slopes. The analysis also shows that the installation of retaining walls to increase the length of the seepage path is effective to prevent slope failure induced by seepage flow. The effects of water flow on soil nailed slopes, locally loaded slopes and pile reinforced slopes are also investigated in this study. The present study also shows that the effect of densely populated soil nail on the seepage flow can be neglected for practical purposes.