Optimization Of Train Line Plan For National Holiday Of High-Speed Railway

High-speed railway has become a popular travel mode due to its advantages of fast speed,great carrying capacity,high safety and good travel conditions.After the promulgation of the statutory holidays,holiday travel demand for high-speed railway surges,which puts forward higher requirements for holiday line plan.Current holiday line plan is made by artificial decision-making method.The actual method that only adjusts train marshalling and adds weekends and holidays trains based on weekday line plan,has two adjustment measures,poor flexibility and low adaptability to holiday passenger flow.Consequently,this thesis mainly studies the holiday line plan optimization of high-speed railway to provide a more scientific optimization method.Firstly,this thesis analyzes the features and influencing factors of holiday passenger flow on high-speed railway.The domestic and foreign holiday line plan of high-speed railway are introduced.Learning flexible optimization experience from foreign countries,this thesis proposes the optimization method of holiday line plan which takes the whole holiday as study period and bases the weekday line plan to optimize holiday line plan by retaining,canceling and adjusting trains.The multi-objective 0-1 programming model of holiday line plan is established with the goal of the minimum railway operation cost and the minimum change of the weekday trains.The decision variables are train operation selection,stop optimization and marshalling optimization.Then,hierarchical sequence method is adopted to transfer multi-objective programming into single-objective programming based on the comparison and analysis of some multi-objective methods.The optimization model of holiday line plan for high-speed railway belongs to the NP-hard problem.Decomposition method and relaxation iterative method are designed in this thesis according to the characteristics of the model.Decomposition method decomposes the problem into two sub-problems,potential train set generation and train optimization.Relaxation iteration method relaxes 0-1 variables to continuous type,and combines branch-and-bound algorithm and iterative idea to solve the 0-1 programming model,which can improve the efficiency of the model.Finally,this thesis studies the line plan optimization case of Beijing-Shanghai high-speed railway during QingMing Festival in 2015.After analyzing parameter sensitivity and optimization rules,including weekday-train running ratio,stop optimization rules and stop adjustment parameters,the optimization model and algorithm proposed in this thesis are used to solve the case problem.Three contrastive scenarios are set.Scenario 1 compares optimized result with actual line plan.Scenario 2 analyzes the difference between changeable-stop plan and fixed-stop plan.Scenario 3 is the line plan comparison of whether considering EMU connection time.The analysis result shows that optimized holiday line plan spends fewer railway operation cost,maintains the similarity to weekday line plan and improves the railway service level.The case verifies the effectiveness and rationality of the proposed model and algorithm.This thesis provides the mathematical model and algorithm reference for holiday line plan optimization of high-speed railway.