Study On Prediction Criteria Of Bazimen Landslide In The Three Gorges Reservoir Area

The landslide is a serious deformation phenomenon, which can cause great loss to the life and property as a natural geological disaster. Our country is a country with much many geological disasters, so it is a good way to predict and prevent those disasters.The keys of landslide prediction are prediction method and prediction criteria.Once the prediction method is determinered, the landslide can not be predict correctly without the correct prediction criteria.It is difficult to establish the prediction criteria, and many prediction criterias have been studied by some researchers around the world.but any of these prediction criterias has its limitation,and can not be as a uniform index to predict landslide.So the study on the prediction criteria must be established on the basis of deeply research for landslide type, characteristics,deformation features and the forming mechanism ,together with the monitoring data, then find out the major effect factor for the landslide stability.Finally,the practical prediction criteria can be obtained.this article is taking the Bazimen Landslide as an example to study.Study the engineering geology exploration data carefully, make know the landslide type, characteristics, and deformation mechanism, then find out the major factor for the landslide deformation.The major effect factors of the landslide stability are the reservoir water repeated lifting and rainfall, which can affect the geotechnical strength, groundwater line and water pressure of the slope.In order to determine the effect by the water pressure of the slope, the simplified unground water line calculation formula is taken to calculate the underground water line of the slope, which is the preparation for the landslide wholly stability calculation.In order to determine the effect degree to the landslide stability by each factor,the way of limited equilibrium is taken to calculate the landslide stability under different impounding height,different water decreasing speed and different rainfall strength. In order to determine the deformation features of different position of the landslide, the finite element software GTS is taken to analysis the landslide doformation feature in the condition of the critical state.The level displacement value of feature point on the slope body is got under the condition of critical instability.The value will be taken as the prediction criteria of the landslide. On the basis of research results above, the impounding height, water decreasing speed, rainfall intensity, the deformation value of feature point on the slope body, together with some macroscopic phenomena of slipping time are taken as the predictiong criteria for the Bazimen landslide, which can be taken to predict warning the landslide, and its method and conclusion can be referred for other similar projects.