Research On Railway Line Selection Strategies And Optimization Method In Loess Gully Region

In Mid-long Term Railway Network Plan(NDRC,2016),the state council proposed to continue to implement western development strategy,focusing on the implementation of the Silk Road Economic Belt and the 21st-Century Maritime Silk Road,and put forward a clear construction plan for the central and western regions to improve the road network layout and balance the regional layout.However,the complex geological conditions and fragile ecological environment in the loess region in central and western China have brought many difficulties and challenges to railway line selection and design.Therefore,it is of great significance for railway construction in the central and western regions to carry out research on railway line selection strategy and comprehensive evaluation of railway line selection scheme in the loess gully region.This paper mainly studies the railway line selection strategy and scheme optimization in the loess gully region.Firstly,the distribution,geomorphology and characteristics of loess and the geomorphologic and geological characteristics of loess gully areas are summarized.This paper analyzes the genetic mechanism and characteristics of various undesirable geological features in loess gully region,and studies the prevention measures in engineering construction.The paper also gives some suggestions on railway line selection strategy from five aspects: technical feasibility,bad geological conditions,economic rationality,environmental protection and social influence.Then,according to the railway line selection strategy proposed in this paper,combining with the special geological conditions of the loess region,the evaluation index system of the loess region line scheme is established by selecting specific indexes from four aspects:technology,economy,environment and society.Based on the comparison and analysis of the methods commonly used in multi-objective decision making,combining with the characteristics of line selection in loess gully region,the improved close-value method of analytic hierarchy process(AHP)was selected to determine the weight,and the optimal model of line planning in loess gully region was constructed.Finally,the introduction of Yanan-Yulin High-Speed Rail project cases,combined with the selected index system,this paper using the calculation and analysis of building optimization model,validation results show that the established index system of rationality,build the optimization model has reliability and practicability,the comprehensive evaluation of railway line selection of the loess hilly areas has reference value and practical significance.