Hazard Assessment Of Geological Hazards Along Jing-Zhang High-Speed Railway

New Jing-Zhang high-speed railway is not only an important supporting transportation infrastructure for the 2022 winter Olympics in Beijing,but also an important part of the eastern section of the "eight vertical and eight horizontal" Jinglan corridor that the state plans to implement.However,the external environment of the line crossing area is complex and the geological background is varied,which makes the new Jing-Zhang high-speed railway facing the potential threat of landslides,landslides,debris flow and other geological disasters.Based on the survey data of geological disasters along the Jing-Zhang high-speed railway,the development and distribution of geological hazard points along the railway are investigated,and the quantitative index system of the main influencing factors was set up.The risk assessment of the geological hazard of Jing-Zhang high-speed railway was completed.The main research works of this paper are as follows:(1)The background conditions for the formation of geological hazards along the Jing-Zhang high-speed railway were preliminarily revealed.By collecting the geological data of the topography,geomorphology,and lithology along the Jing-Zhang high-speed railway,the regional geological structure background is analyzed and studied in combination with the interpretation of remote sensing images.The formation conditions of the existing geological disasters in the region are studied.The development types,distribution characteristics and space-time distribution rules of line geological hazards are discussed.(2)The control and influence factors of geological hazards along the Jing-Zhang high-speed railway have been completed,and the risk assessment factors for geological hazards have been determined.Considering the dynamic geological conditions inside and outside the study area and the development characteristics of geological disasters along the railway,11 factors,such as geological structure,peak acceleration of ground motion,rainfall,vegetation coverage,engineering geological group,water erosion,topography and geomorphology,human engineering activity,are selected as the main evaluation factors of geological hazard assessment.(3)Based on the random forest model and analytic hierarchy process(AHP),and combining with the distance function method,a new combination weighting model(RF-AHP)is proposed.On this basis,the risk assessment of the new Jing-Zhang high-speed railway geological hazard is completed,and the results of the evaluation are compared with information value method.(4)The formation mechanism,movement mechanism and accumulation process of debris flow in canfingying gully are studied.On the basis of field investigation and testing of rock and soil mechanics parameters,and based on Flo-2d software,the starting and evolution process of debris flow,accumulation and the threat to G7 expressway are calculated under the 10,20,50,and 100 year rainfall conditions of the Canfanying.