Research On Optimal Selection Method For Green Railway Alignment Selection Of High Speed Railyway In Southwest Mountainous Area

According to the middle and long term railway plan of china, high-speed railway network will cover most areas of our country, including southwest mountainous areas. Due to the unique features of geography, culture and economic environment in southwest mountainous areas, the green degree of permanent way is received high attention, therefore, green railway alignment selection confront heavy tasks and a huge challenge. With the beginning of high speed railway construction in southwest mountainous areas, whether green railway route selection is reasonable becomes especially important.At present, high speed railway alignment selection is mainly based on economic evaluation along with a low regard for environmental factor, the compatibility between selected route and environment along the route is not considered comprehensively. Furthermore, theories of green railway route selection are still immature and lack combination of the construction project. So, conducting optimization research on high speed green railway route selection within southwest mountainous areas has great significance both theoretically and practically.The paper presents research results of green railway alignment selection theories at home and abroad as well as railway line scheme evaluation method based on green railway alignment selection theories. After analyzing and Screening a variety of system evaluation and optimization method of scheme, combined with features of southwest mountainous areas, improved osculating method is introduced to study the scheme optimization of high speed railway route selections.First, the paper discussed green route selection theories and conducts a comprehensive study on factors of high speed green railway route selections in southwest mountainous areas. After screening these factors in accordance with the relevant principles, three optimization index systems are established according to natural environment, economic environment and social environment separately.Then, the paper analyses a variety of multi-objective decision-making methods and characteristics of different optimizing targets, a more reasonable weight-decision method is selected. In addition, Entropy Method is introduced during the procedure of scheme optimization and sorting, which ensures a reasonable, comprehensive and objective result while simplifying optimization process. At last, the application of route schemes evaluation and optimization using improved osculating value method is discussed and a case study of Cheng-Mian-Le Passenger dedicated line (Jiang you to Mian yang) is also introduced. The results show that this method has definite reference value in evaluation and optimization of high speed green railway route selections as well as production practice in southwest mountainous areas.