Multi-objective Optimization Of The Maximum Gradient For The Mountai Section Of A Passenger-dedicated Railway Line

The High-speed Railway Design Standard regulated that the design speed, main line distance, minimum radius of plane curve, maximum gradient, arrival and departure track length, train-set type, train running control mode, train traffic control mode and running interval are the main technical standards of high-speed railway design. As passenger dedicated line using train-set with a strong climbing adaptability. The selection of maximum gradient has greater effect on line alignment, length, engineering investment, operation fee, hauled weight and delivery capacity in the mountain section of long main line, even directly determine acceptability line scheme. So how to choose maximum gradient become difficult problem to compare with other standard.This paper was combined with engineering practice of the maximum gradient for the mountain section of Xian-Chengdu passenger dedicated line, using multi-objective decision of fussy comprehensive evaluation researched the selection of the maximum gradient. This paper focused on the following aspects of the research work.(1)Combing with engineering practice of Xian-Chengdu passenger dedicated line, this paper has been analyzed and compared the various factors effecting the selection of maximum gradient, reached on the effect of different maximum gradient(20‰,25‰,30‰). This paper emphatically further study on adaptive capacity along the terrain, train-set adaptability of different maximum gradient, maximum gradient scheme with adjacent lines adaptability and technical economy aspects of maximum gradient scheme, and covered some detailed technical comparison amony train-set speed, kinetic energy rush gradient and operation, we obtained engineering investment comparison of different gradient scheme as decision basis.(2)Based on the existing research of multi-objective evaluation method, multi-objective fuzzy evaluation method and evaluation index suitable for the selection of passenger dedicated line were chosen. A study on algorithm principle and solving process of multi-objective fuzzy evaluation method were carried out based on the detailed analysis of analytic hierarchy process and fuzzy evaluation theory. This paper established the scheme comparison and selection model of maximum gradient for the mountain section of a passenger-dedicated railway line, by choosing suitable evaluation index and evaluation system of comprehensive evaluation line scheme work and establishing two level evaluation index system, among them, economy, technology and environment as the first layer evaluation index, engineering investment, operation fee, speed adaptability, rush slope simulation, operation simulation, topography alongside, maximum gradient adjacent existing lines and restrictions for second adaptability evaluation indexes. Fuzzy mathematics theory combained with analytic hierarchy process in the moden, it can obtains accurate results through considering the influence of many factors, and thereby analysis and optimization of multivariate and multi-objective problems can be done more scientifically and reasonably.(3)In order to validate the correctness of the algorithm, this paper using multivariate and multi-objective fuzzy-analytic hierarchy model to establish maximum gradient for the mountain section of a passenger-dedicated railway line evaluation model, design flow chart of system framework, compile visual multi-objective fuzzy-analytic system by use VB. The model can realize the weight calculation and preference values of index factors, formate optimization value of matrix and calculation process of comprehensive evaluation result. Every evaluation fator and evaluation index of optimization value and weight matrix can real-time display in calculation process, that can be used to evaluate data rationality and ensure reasonability of scheme evaluation.This system was used to compare selection different protocol information in maximum gradient selection process of Xian-Chengdu passenger dedicated line, the calculation consistent with those of engineering example, so the algorithm is feasible. The study of paper and the development of system have an important practical value for enhancing scientific in evaluation work of maximum gradient scheme of passenger dedicated line. In addition, the system can be used in evaluation process of other line schemes and have a certain popularization and application value.