基于加权绕行度的铁路网布局优化方法研究

Railway Network Layout Optimization Method Based on Weighted Detour Degree

路网布局优化是铁路网规划的关键步骤之一。在多年铁路网规划研究实践中,布局优化主要采用基于项目的优化方法,这一方法将每个规划项目视为孤立个体,忽略了项目之间在路网上的关联,并存在部分指标难以定量化、需依赖专家经验等问题。随着铁路网由规模速度型向质量效益型发展,在项目的规划决策阶段将更加注重优化方法的系统性和客观性,这对优化方法提出了新的要求。研究立足路网视角,以最小化全网加权绕行度为目标,以规划规模为约束条件,建立了基于路网加权绕行度的网络优化双层规划模型,能够实现对备选规划项目集合的组合优化,并为多种规划方案的横向对比提供量化指标支撑。通过成渝地区高速铁路网布局优化案例研究,对不同规划规模约束进行了多场景模型求解,并分析了优化结果,验证了方法的有效性和可操作性。

Network layout optimization is a crucial step of railway network planning.During years of railway network planning research practice,the project-based optimization method is mainly adopted,which regards each planning project as an isolated individual,and correlation between projects in the network is out of consideration.Besides,problems that some indicators are difficult to quantify and rely on expertise are also the weakness of this method.As the development of railway networks transforms from scale-and-speed-pursuing to quality-and-benefit-pursuing,more attention will be paid to the systematicness and objectivity during the decision-making stage of projects,which put forward new requirements for optimization methods.Based on the perspective of the whole network,a bi-level optimization model was built,which aimed at minimizing the weighted detour degree of the network with the constraint of planning scale.The model can optimize alternative projects combinatorially and provides the quantitative index for horizontal comparison of various planning schemes.Through the case study of high speed railway network layout optimization in the Chengdu-Chongqing area,the multi-scenario model was solved for different planning scale constraints and provided elaborate analysis.Therefore,the effectiveness and operability of the model were verified.