关键词: 道路工程； 路基滑坡； 强度折减法； 数值模拟

Abstract: Taking the landslide of soft soil subgrade reinforced by pipe pile of an expressway in Hubei Province as an example, according to the current situation of on-site stratum bias, the landslide sliding area was simulated by using the finite element software GTS NX and the corresponding safety factors were obtained, to explore the rationality of construction and alternative schemes.The test results show that: ① The landslide is not caused by insufficient bearing capacity, but by the uneven distribution of soil layer.The post-treatment scheme does not fully consider the adverse effects of soil bias, which causes the reinforcement of soft soil subgrade is invalid.② In the proposed model, the main slip zone appears in the lower area of the access road near the water side of the subgrade, which drives the slip of the adjacent areas.③ The vehicle load has no significant effect on the landslide, while the pond water pressure effectively offsets part of the lateral pressure to improve the safety factors.④ The pipe pile at the bottom of the subgrade can effectively reduce the bottom displacement, and the pipe pile at the edge of the access road will significantly improve the safety factors.

Key words: highway engineering; subgrade landslide; strength reduction method; numerical simulation