The Study On Geological Disaster In The North Slope Of Qin Ling Mountains

With the implementation of the strategy for the development of the western regions, the issue of slope geological disaster prevention has been more prominent. On the North Slope of Qin Ling Mountains, due to locating in unique crust geodynamics environment and under the action of fault activities, long-term strong new tectonic movements and exogenetic force, geological disasters such as rock fall, landslide and debris flow etc. extremely develop. Therefore, in order to prevent inducing slope geological disasters, engineering geological environment and ecological environment protection should be paid more attention when advocating the large-scale engineering economic activities.From the viewpoint of geological environmental characteristics of the North Slope of Qin Ling Mountains, the main geological disasters in this region and its development and distribution are analyzed. Taking peony garden landslide in Hu County for example, genesis mechamsm of the peony garden landslide is also analyzed. Based on site exploration and test results, using combined methods of geological analysis, stability assessing and numerical simulation, genesis mechanism and stability conditions of the peony garden landslide are argued. And control measures are studied and the optimal control plan is determined.The results from the investigation of peony garden landslide and geological analysis show that the peony garden landslide is a old thrust load caused soil landslide with medium sized, located in the posterior edge of foreland pluvial fan of Qin Ling. The east- west width of the landslide is 100-150m and the south-north length is about 220m with the average thickness of about 20m.The landslide consists of loess soil and silty clay. Calculation of landslide stability shows that landslide is stable in the native state. While under the conditions such as earthquake, sustained rainfall and human effects, old landslide could fail. Simulation results of landslide show that stress-strain of landslide posterior edge is greater and the front and toe of landslide has a protective effect or effect against sliding for its stability.According to deformation of the landslide and with the characteristic of greater thrust force in rainfall and earthquakes, considering the construction of local tourism scenic spots, based on studying of control plan, the comprehensive control plan of anti-sliding pile and drainage is chosen, and the relevant parameters on control plan are computed in detail.Evaluation methods of the landslide stability and prevention measures of the landslide proposed in this thesis provide a reference for studying landslide geological hazards occurred on the North Slope of Qin Ling Mountains.