Study On High-Speed Railway Minimum Curve Radius Based On The Integrated Optimization Method

The minimum radius of circular curves in railway lines is the minimum value of radius among all circular curves in railway location design. This value not only has influence on indicators of driving quality like trains running safety and passengers’comfort, but also on indicators of railway operation technology like driving speed and operation time and indicators of economies like construction investment, Operating expenses, and economic benefit. A smaller value of radius can make lines adapt to topography better, bypass possible barrier, reduce the ratio of bridges and tunnels in lines. Consequently, the construction expenses can be reduced. However, if the value of radius is too small, conditions of railway operation and maintenance will be terrible and operating expenses will increase substantially. As a result, how to choose an appropriate value of radius to keep balance between construction expenses and operating expenses is a significant issue.In order to overcome the issue that values of radius which come from Dynamic Simulation Research can’t guarantee the economy of projects, this thesis builds a mathematical model based on the results of dynamic simulation computing and engineering optimization technology in which economic effects are the target function, and computes the best value of the minimum radius of circular curves based on relative mathematical methods. The main contents and achievements are listed below:1) This thesis makes the results which come from Dynamic Simulation Research as decision variables, including the minimum radius of circular curves in railway lines, the minimum length of grade sections, and the value range of the maximum design grade. This thesis does the job of railway location, designs lots of feasible plans which have different combinations of design variables, and computes the economic indicators of all feasible plans.2) This thesis analyses the influence of decision variables on the economical efficiency and practicability of projects based on the analysis of economic indicators of all feasible plans. Besides, this thesis finds the relationship between decision variables and economic indicators, and builds corresponding mathematical models.3) This thesis makes the operating expenses of projects as the target function, the minimum radius of circular curves, the minimum length of grade sections, and the maximum design grade as decision variables, transport capacity and other threshold values in the standards as constraint conditions, and computes the best economic value of the minimum radius which can guarantee driving safety, passengers’comfort, and stability based on the mixed discrete complex method. Eventually, this thesis compares the results with standards of high-speed railway design and gives some suggestions about that.