Abstract：A serious landslide occurred in a slope in Shenzhen due to the continuous rainstorms. The landslide generation mechanism is studied and the treatment scheme is discussed accordingly. Based on the investigation information，the slip surface is found in the contact interface between highly and medium- decomposed marble. The contact materials have become saturated due to rainwater infiltration. And most cohesive particles are washed away by the infiltrated rainwater flow. The serious lost of cohesion，thereby，has weakened strength of the entire slope body and caused a landslide. The numerical model is established for back analysis according to the slope characteristics and the compution values of strength parameters have also confirmed the cohesion reduction due to rainwater infiltration. In addition，discussions are conducted on the influence from different contact interface angles to evaluate the slope stability. The correlation between the contact interface angle and the calculated factor of safety do not tend to be monotonous，which would be an important factor affecting the slope stability. The slide-resistant piles with anchors are applied as the new reinforcement design to prevent the slope failure in consideration of the importance of oil tanks and power transmission tower adjacent to the slope. The information monitored after several heavy rainstorms shows that the slope deformation has been well controlled. It is approved that stability of slope has been improved and the landslide is well treated. Some experiences from this project can be referred for slopes stability analysis and treatment design under similar rainstorm conditions.
