突发环境下城市道路网关键路段集识别

为了更好地判断出突发环境下城市道路网络中的关键路段，本文结合路网脆弱性分析方法，构建了一种涵盖单条到多条路段失效的关键路段集识别模型.首先，对路网进行随机攻击，运用网络效率、最大连通子图等鲁棒性指标寻找潜在关键路段；然后，引入0-1变量，建立一个含道路通行能力约束的非线性优化模型；再以此为基础，用分段线性化手段处理目标函数与约束条件，将模型转化为一个混合0-1规划问题；最后，以分支定界法求解模型并设计算例验证.结果表明：突发环境下的路网关键路段集一般不是若干关键路段的简单集成，其构成元素在几何拓扑层面上也不具有邻接关系；而且随着失效路段数的增多，路网鲁棒性与总阻抗变化量之间会呈现出较显著的负相关关系，可用“逆向”曲线进行刻画，效果良好.

Identification of Urban Road Network’s Critical Links Set under Emergency Environment

In order to determine critical links of urban road network better under emergency environment, this paper combines with network’s vulnerability analysis to structure a critical links’ identification model, which covers single and multiple failure links. Firstly, getting random attack on network and using network efficiency and maximal connected subgraphs to find potential critical links; then, introducing 0-1 variables to establish a nonlinear optimization model with road’s capacity; on the basis, handled objective function and constraints by piecewise linearization and translating the model into a mixed 0-1 programming problem; finally, using branch and bound method to solve model and an example is given to verify it. The results shows that: the critical links set is not a simple integration with single critical links, whose constituent elements don’t have adjacency relationship each other on geometric topological level. But with the number of failure links increasing, there is a significant negative correlation that can be described by reverse curve between the robustness of network and its total impedance variation, which owns well-tried effect.