Research On Optimal Selection Method Of High Speed Railway Line Planning And An Empirical Analysis

Railway route selection is the first important problem to be solved in the railway design stage,which is related to the investment,quality,time limit and the effect of the whole railway design.At the same time,it will affect the economic development along the railway and passenger and cargo transport.In addition,the local environmental impacts are also very different for different routes.At present,our country is developing environment-friendly and resource-saving society,the optimization of railway lines must conform to the conservation of resources as much as possible,and decrease the destruction of the environment as much as possible.Therefore,in the design of the railway line selection scheme than the election stage,under the premise of ensuring the feasibility and quality safety,must optimize the comprehensive scheme for each line,and then make sure the final plan is the best plan to meet the needs of the parties.This paper presents the use of grey theory and TOPSIS theory of the improved RSR method to optimize railway line scheme,consider all kinds of factors,so as to select the most practical,the most ideal solution.First,establish the index system of railway plan optimization.In the establishment of the index system,we should consider four factors: technical factors,economic factors,environmental factors and social factors.In these four factors are divided into 20 specific indicators.Indicators and indicators are mutual independence,and do not interfere with each other.Each indicator can independently reflect a particular feature of the project.Then use the entropy method,according to the difference between the various programs to the index weight.Secondly,by comparing the advantages and disadvantages of rank sum ratio method,grey correlation method and TOPSIS method,in this paper,the grey correlation method and the approach of TOPSIS method are used to improve the rank sum ratio method,so that the original rank sum ratio method can only be considered "quantity" without considering the shortcomings of " direction",but it retains the original advantages of the method.This method makes use of the membership degree in fuzzy mathematics to quantify the qualitative indexes,construct the decision matrix,and standardize it.Weighting matrix is formed by combining the weights of each index.The grey correlation coefficient matrix is established by using grey correlation theory.On this basis,each scheme as an n-dimensional vector,to construct the positive and negative ideal vector,thus the idea of using the degree of similarity in TOPSIS method,calculate the similarity degree of a vector and the ideal vector,thus to improve the weighted rank sum ratio,which makes the method of weighted rank sum ratio method is more scientific and reliable.Finally,choose the line from Beijing to Xianghe section of Jingtang route selection as an example,optimization of railway route scheme by improved weighted rank sum ratio method,the results are consistent with the results of the design unit;by comparing the results with other methods,the rationality and feasibility of the proposed method are verified.Compared with the commonly used method of conversion project operation fee,to optimize the railway scheme using grey theory and ideal theory of the improved weighted rank sum ratio can more objectively reflect the impact of indicators on the evaluation target,make the results more convincing,which provides a reference for the optimization of the railway route.