The Application To Comprehensive Evaluation Of Railway Location Scheme Based On Grey Incidence Improved TOPSIS

The line selection is an overall job that concerns the whole in railway engineering design. While, the comparison and selection of the railway line scheme is a critical part in this job, for it’s not only covers a wide scope but also involves the comprehensive apply of multi-disciplinary. In addition, there are both quantitative and qualitative indexes in this part, such as environment, social and some other qualitative indexes. So, in the process of the railway line scheme comparison and selection, a thorough investigation must be made in practice and sufficient materials be collected, then a multi-goal and comprehensive evaluation could be conducted finally.In this paper, the author puts forward the TOPSIS method based on Grey Correlation in making line scheme comparison and selection, and targeted at the best scheme in the study of comprehensive evaluation of line scheme.Firstly, the paper will establish a comprehensive evaluation index system through analyzing virous factors that affect the line scheme comparison, which is consists of four criterion layer(technology, economy, environment, society) and nineteen detailed index layer it owns. At the same time, the paper will make a detailed introduction of the way of solving the index weight by applying AHP method and build the hierarchy class tree model of evaluation index, also the nine scale method is adopted in building up the judgement matrix to solve the index weight. While the MATLAB program is is applied in solving the eigenvalue and eigenvector, then the weighted value of each evaluation index obtained finally.Secondly, the paper comes up with TOPSIS method that was improved on grey correlation to evaluate the line scheme by analyzing the merits and demerits of both of them. The method using the concept of degree of membership in fuzzy mathematics to assign values to qualitative index and then combine the quantitative and qualitative value together. And, the paper also builds up evaluation matrix and applies dimensionless method to form the weighted matrix. According to the analysis of grey correlation, the paper gets the grey correlation coefficient matrix. On account of this, it determines the positive and negative ideal schemes, and calculates the Euclidean distance between the evaluated objects and the schemes, then it gets the relative proximity degree of each objects at last, and then to evaluate the scheme on proximity degree.Finally, this paper gives an example of line scheme comparison of YuKa period in Dunhuang to Golmud railway to conduct a case study of applying TOPSIS method to line scheme comparison. And, the calculated results are in accord with the route scheme that was used by design units, which verifying the feasibility and rationality of the method that the paper presents in evaluation of route scheme. It can achieve the expected goals and satisfactory results can also be obtained.When compared with the current scheme comparison and selection, which is mainly depends on calculating the cost of projects, the POSIS method, which was improved on grey correlation, can reflect the influence of evaluation indexes upon evaluation targets much more objectively, and the results are more convincing, scientific and reasonable. It really provides some references to optimal selection of schemes.