Abstract: The high and steep slopes along highways are prone to have a sudden hazard such as landslides under the influence of multiple factors as heavy rainfalls and earthquakes. It is crucial to quickly provide the mitigation plans to reduce economic and property losses. This article selects the landslide hazard of a highway slope in Yunnan Province as the case history. The potential sliding surface of the slope and the mechanical parameters of the rock and soil through geological surveys and laboratory tests are determined. Based on the highway slope safety control standard, three working conditions for the engineering practice are established and the stability standard is determined. Two methods are proposed: “prestressed ground anchor reinforcement” and “prestressed ground anchor plus the sheet pile wall combine mitigation”. Based on the required slope safety factor in the specifications, the corresponding design is carried out by using the limit equilibrium method and verified that the slope will remain stable under the above two methods. The results provide a reference for the design and mitigation methods for similar projects.

Key words: High and Steep Slopes, Landslide Mitigations, Limit Equilibrium Method, Prestressed Ground Anchor, Sheet Pile Walls