The Risk Assessment And Prevention Proposal Of Main Geological Disasters For Wanzhou-liangwu Railway

For the railway from Wanzhou to Liangwu (i.e., railway from K157.077to K254.617), the geological conditions have been relatively complicated, and the railway herein suffers a great variety of geological disasters. In this paper, the main geological disasters are studied systematically, including the geological conditions, the types and scale of disasters, the spatial distribution characteristics of these disasters, the factors contribute to them and the mechanism of the development of the disaster. On basis of these studies, the stability analysis and risk assessment are conducted qualitatively and quantitatively, respectively. In addition, corresponding suggestion for prevention and mitigation for these disasters are given in this paper. The main components that this paper covers are as follows:1. The current situation of the geological disasters along the railway from Wanzhou to Liangwu is clarified and summarized. Based on the investigation material for this railway, the types and scale of disasters, the spatial distribution characteristics of these disasters, the factors contributing to them and the mechanism of the development of the disaster are also studied in this area.2. The factors which contribute to the development of the disasters along this railway are analyzed from two different aspects:the internal factors and the outer factors. The internal factors include the geography, formation lithology and geological structure, while the other includes the rainfall, earthquake, human activities and so on.3. This paper puts forward the corresponding qualitative evaluation standards, and then they are applied to this area to assess the level of stability of the disastes.4. On basis of the main geological disasters along the railway from Wanzhou to Liangwu, evaluation index system is established quantitatively for risk assessment of geological disasters. In the system, geological conditions and other conditions are considered as the factors for risk assessment evaluation. Geological conditions refer to the angle between joint direction and the direction of the slope dipping to, dip angle of the unfavorable structural plane, the combination characteristics of the joints, the height of the slope, the angle of the slope, the type of the slope etc., while the other conditions refer to the feasibility of the mitigation method, the scope of the disasters, attitude difference off the railway, the horizontal distance to the railway, daily rainfall and so on.5. AHP-synthetical index method is applied to assess the risk level for the railway from Wanzhou to Liangwu. Subsequently, the result from the above method is compared to that from the experts in present situ. Through the comparison, it is found that AHP-synthetical index method runs reasonably well in this area.6. Prevention and mitigation methods are obtained through the study and analysis for the railway from Wanzhou to Liangwu.