MONITORING DATA ANALYSIS AND ENGINEERING EFFECT STUDY ON WATER-SATURATED LANDSLIDE IN QIN-BA MOUNTAIN AREA

The formation and development of landslide are often associated with the activity of surface water and groundwater. This paper analyzes the deformation mechanism of a water-saturated landslide in the Shitian Highway in Qin-ba mountain area, predicts the failure mode of the landslide after excavation, and formulates the control scheme. The monitoring data analysis at the construction stage and the study of engineering effect are used to verify the deformation and failure mode. Deformation features of the landslide at each construction stage are summarized. The large-scale overburden landslide has plentiful groundwater. The creep characteristics are associated with the rheological property and the stress states of cohesive soil. Higher clay content, larger plasticity index and higher water content of sliding mass cause stronger rheology of soil and more obvious effects on creep deformation in landslide body. It is difficult to control the deformation development of the water-saturated landslide only to take surface drainage engineering and supporting measures. Underground drainage engineering such as discharge tunnel to change the groundwater seepage field and improve the slide zone's effective stress must be complemented when treating the water-saturated landslide. With the deepening of excavation, the strain energy of the slope has been released and the new plastic zone can be formed. Based on the theory of progressive failure, the sliding surface of the large deep overburden landslide reinforcement with anti-slide pile can be enhanced. The treatment project should consider the influence of multilayer surface.