Slope Failure Treatment by Anchor Rod Method at Exit of Tunnel: Case Study in Nanxia Expressway

Slope failure is a severe disaster triggered by natural causes and human activity. To analyze the slope failure that occurred during the construction of Nanxia expressway, this study conducted on-site investigations and carried out tests at the exit of the deep excavation cutting section to reinforce the slope and improve its stability. The results reveal that the slope failure was triggered by excavation and heavy rain during the construction period. The initial design did not consider the specific geological conditions, and heavy precipitation increased the selfweight of the soil. In short, this accident was caused by natural causes and human activity. Using concrete to fill the landslide mass and extend the anchorage depth can enhance the slope stability. Alternatively, four grades of slope reinforcement and anti-slide pile reinforcement methods are also effective ways to reinforce bedding slopes with the same rock stratum inclination. Both design and construction problems can directly result in severe issues. To guide the construction more effectively, the designer should pay more attention to the geological conditions, instead of only focusing on the stability safety parameter.