Research On Optimization Of Railway Environmental Route Selection Scheme In Mountainous Area Based On Set Pair Analysis

The railway is not only the infrastructure and people's livelihood engineering,but also the mainstay of the comprehensive transportation system,which plays an important role in the development of national economy.Since the railway construction has a great impact on the environment along the railway during the construction and operation period,the environmental factors should be fully considered in the line design phase.The line plan not only directly affects the investment cost,construction period and operational efficiency,but also affects whether the railway can meet local transportation demand and the impact on regional economic and social development.In the early stage of construction,the line plan should be comprehensively analyzed to determine the best plan.In addition,the optimization of railway line plan is a complex multi-objective decision-making process,which needs to consider many index factors,is affected by external factors,and has uncertainty.However,the traditional evaluation methods are mostly based on deterministic analysis,without considering the uncertainty of evaluation decision-making.Therefore,it is of great significance to compare and evaluate the railway line plan in mountainous areas according to the uncertain characteristics and considering environmental factors.To this end,this paper constructs a comprehensive evaluation model based on set pair analysis method for environmental railway route selection in mountainous areas,and applies the model to an engineering example.Firstly,this paper investigates the environmental problems related to railway construction by comprehensively analyzing the influences of railway construction on the natural environment,ecological environment and landscape environment along the railway.In addition,this paper studies the connotation and characteristics of environmental railway route selection,and summarizes the general principles and design steps.Then,this paper researches principles and methods of index system construction,and determines to use the modeling idea of target decomposition method and the analytic hierarchy process.to build the evaluation index system.On the basis of considering the technical and economic characteristics of the line plan and the influence of social benefits,a more comprehensive evaluation indicator system is preliminarily established from the perspective of environmental protection and sustainable development.Secondly,this paper discusses the commonly used index screening methods.By analyzing the advantages of rough set theory in attribute reduction,this paper determines to use the attribute reduction algorithm based on information entropy to screen evaluation indexes.In addition,a method based on weighted least-square method and fuzzy entropy weight method is proposed to calculate the weights of indexes.Thirdly,by comparing the common comprehensive evaluation methods and researching the applicability of the set pair analysis theory in line optimization design,this paper constructs a comprehensive evaluation model based on set pair analysis method for environmental railway route selection in mountainous areas.Finally,this paper uses the comprehensive evaluation model to evaluate the line plan of Changdu to Bomi on the new Sichuan-Tibet Railway,and obtains the ranking of the line plans and the optimal line plan to verify the applicability of the evaluation model.Compared with other comprehensive evaluation methods,the set pair analysis method can deeply explore and analyze the uncertain factors in the indicators.Therefore,the comprehensive evaluation model based on the set pair analysis method makes the evaluation results more scientific and reasonable,and provides some reference value for other optimization decision-making problems of mountain railway line plans based on environmental route selection.