FEM STABILITY ANALYSIS OF LOESS SLOPE WITH TUNNELING EROSION

The tunneling erosion is not only a unique mode of soil erosion,but also usually an important factor to the stability of the highway slopes of unsaturated loess in the loess plateau. Based on the developed program of the strength reduction FEM with matric suction,this paper comparatively studies the different cases of the unsaturated loess slope stabilities. The results reveal the possible different effects on the stability of unsaturated loess slope by erosion tunneling as well as matric suction. The results indicate that when their occurrence nears the slope crest,the tunnel erosions prefer to maintain the stability of the slope. On the contrary,when their occurrence nears the slope toe,the tunnel erosions prefer to reduce the stability of slope especially as the tunneling is serious. The results also indicate that the safety factor of the unsaturated loess slope increases and the potential sliding surface moves downward when the matric suction is considered,while the safety factor of the unsaturated loess slope decreases and the potential sliding surface moves upward when the matric suction is ignored.