层状岩质边坡中最不利滑裂面迁移现象的研究

Study on the Transition of the Most Dangerous Slip Surface in Layered Rocky Slope

在阐述层状岩质边坡最不利滑裂面迁移现象的普遍性和研究意义之后 ,分析了边坡结构类型、潜在滑动面阻滑作用、荷载、开挖、水文地质条件变化、预应力锚固和挡墙支护对边坡最不利滑裂面迁移的影响 。

In engineering practice, the safety of slope is described generally by the stability safety coefficient. Each coefficient is corresponding to specific sliding boundary. In order to evaluate the stability of slope rightly, the most dangerous slip surface must be exactly determined in advance. Factors such as excavation, load and reinforcement affect engineering slope stability greatly. They often cause the change in the most dangerous slip surface, make evaluation difficult and even lead to wrong conclusion. In this paper, based on engineering practice, factors caused the phenomena, including structure type of slope, resisting action of the possible slip surface, loading, excavation, hydrogeology condition, prestressed reinforcement and bulkhead support. And then take Jiangyin Bridge Project as an example, effects of loading and excavation on the dangerous slip surface are discussed. The FEM calculation results based on interference displacement showed that, under the action of vertical load of 1.2×10 6 kN ,the most dangerous passive slip surface of south tower foundation slope moved 30 meters downward. Excavation made the most dangerous slip surface of the man made slope in south tower zone moved 6 meters downward. The FEM calculation of water inlet slope in Xiaolangdi Project showed that engineering excavation made the most dangerous slip surface moved from deep to surface.