Study On Optimization Method Of Railway Location Scheme In Mountainous Disaster-prone Area Based On Value Analysis

With the gradual implementation of China’s “traffic power” strategy,a large number of railways will be built in mountainous areas.Mountainous terrain is steep,geological conditions are complex,and mountain disasters occur frequently.Disaster prevention and mitigation measures such as bypassing and replacing roads with bridges and tunnels are adopted in railway design.However,the construction cost will be increased greatly due to the adoption of relevant disaster prevention and mitigation measures.How to balance the relationship between disaster reduction capacity and construction cost is a difficult problem to be solved in the process of mountain railway design.Therefore,in view of the research stage of railway line scheme,the optimization method of railway line scheme was constructed in mountainous disaster-prone areas from the perspective of disaster reduction and economy.Thus,the railway design scheme with the best comprehensive benefits of safety and economy was determined reasonably.The main research work is as follows:(1)The MIC method was used to calculate and select the key indexes which have great influence on the project cost in the research stage of mountain railway line scheme.And the key index system of mountain railway project cost estimation was constructed.Combined with CNN,the MIC-CNN estimation model of railway project cost in mountainous areas was established,and the estimation results were compared with those of BP neural network and CNN model.This verified the superiority of MIC-CNN model and provided a basis for the calculation of cost coefficient of railway location scheme in mountainous areas.(2)The influencing factors of disaster susceptibility and line vulnerability along railway line are systematically analyzed.And the selection method of geological disaster risk evaluation index for mountain railway areas was proposed.According to the disaster mechanism of major geological disasters along the line,18 primary indexes of landslide,collapse and debris flow susceptibility evaluation were obtained.And then the index reduction model based on clustering-genetic-rough set algorithm was established.The model was used to remove redundant primary indexes,and construct the disaster susceptibility evaluation index system.At the same time,considering the exposure,disaster bearing,recovery and replaceability of the line,the vulnerability evaluation index system of the line was constructed.(3)A geological hazard risk assessment model of mountain railway was established,which considered both disaster susceptibility and line vulnerability.The "30 × 30m" raster cell is used as the basic unit for calculating the hazard susceptibility and line vulnerability indices.A calculation method of geological hazard susceptibility index of mountain railway line based on analytic hierarchy process and information content method,and a calculation method of line vulnerability index based on analytic hierarchy process were proposed.(4)Based on the principle of value analysis,combined with the engineering cost estimation model and the geological disaster risk evaluation model of mountain railway,the value coefficient of relevant railway line scheme was proposed.And the optimization method of railway line scheme in mountainous disaster-prone areas was constructed.The feasibility of the method was verified by engineering examples.