Research On Forming And Preventing Measure Of Typical Landslide In Zigui County In The Three Gorges Reservoir Area

After the hydraulic project of the Three Gorges of the Yangtze River is completed, the water level in front of the dam of the Three Gorges reservoir area will be raised from the now several tens of meters to175meters. Furthermore, because of the needs of preventing floods, the water level of reservoir area will be adjusted periodically between175meters and145meters every year. This will inevitably cause the revival of part ancient landslides and the formation of new landslides, which will definitely influence the urban construction, the traffic transportation, the people’s life and property security, etc. In the Three Gorges reservoir area, to analyze thoroughly and systemically the stability of the bank landslide, in order to provide the theoretical basis for coming up with the dredging measure of the bank landslide.The three Gorges reservoir areas have complex natural and geological conditions, vulnerable ecosystem and are played with frequent occurrence of flood and rainstorm. The geological hazards are serious. Qianjiangping landslide, Shuping landslide and Baijiabao landslide, which are typical of its kind, situated in Zigui county which is notorious for frequent occurrences of geological disasters in the Three Gorges Reservoir area. Based on the survey of geological conditions and features of above three large landslides, this paper concludes the five main inducing factors for landslides in Zigui country, thus bank slope structure, how the landslides come into being and the collapse causes related to each factors are thoroughly discussed. With this understanding, some measures to control the landslides are proposed. Combined with the principle of prevention first, the importance of landslide monitoring is concluded. At the last part, by using the plane finite element method and limit equilibrium theory, the stability and leading inducing factors of the No.2Landslide of Toudaohe River, which is taken as an example, are analyzed. The results show that the No.2Landslide of Toudaohe River is basically stable under its natural state, but when the reservoir water level rise, the factor of safety of this landslide is about1.2and it has a very high possibility to collapse. In view of the leading factor for the No.2Landslide of Toudaohe River, the reservoir water level rise, two corresponding control measures are proposed. The calculation results show that after strengthen, the factor of safety improved obviously, but the safety reserves are still not big enough, the support measures should be optimized.This specification is set for the theses of Chengdu University of Technology.(1) Zigui country is one of geological disaster-prone areas in the Three Gorges reservoir, with frequent landslide, large destructive and endangering people’s lives and property. Qianjiangping landslide, Shuping landslide and Baijiabao landslide, which are typical of its kind, situated in Zigui county which is notorious for frequent occurrences of geological disasters in the Three Gorges Reservoir area. Specific terrain conditions, the specific geological structure, and weak and weak white combination of internal factors are the formation of landslide; continuous heavy rainfall, the reservoir water level elevation and precipitation caused by other external water infiltration, etc. is caused by the continued decline the external factors.(2) Landslide induced by factors from the start, the formation of Zigui country landslide predisposing factors include the geological structure and weak white combination, groundwater effects, the impact of water level fluctuations, rainfall-induced landslides and earthquakes, geological structure and combination of which is internal and groundwater, the water level fluctuation, rainfall and earthquakes as external factors. In addition, the role of human engineering is also caused some landslides to form an important predisposing factor.(3) Through the Three Gorges reservoir area Zigui country landslide disaster prevention measures analysis, can be drawn:the Three Gorges reservoir area Zigui country landslide control the overall goal is to take comprehensive improvement measures, tackling the problem; landslide to the principle of prevention, treatment of auxiliary, and strive to possible trouble; commonly used control measures can be divided into changes in slope geometry, drainage works, retaining works and change the nature of the soil.(4) In addition, landslide control works should be organically combined with the landslide monitoring work, in the process of governance and the implementation of landslide control works within a certain period of time required to strengthen the monitoring of the deformation of the landslide, the landslide boundaries and landslides around the body to establish an effective monitoring network in professional and technical personnel assigned to carry out landslide deformation monitoring should also be active involvement of local people to start on the landslide body mass monitoring and preventing, and would be an effective early warning and forecasting, to ensure the safety of lives and property of local residents.