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交通网络是国民经济发展的基础支撑,其运行的安全、稳定问题已成为关注重点。为识别网络中的薄弱环节,本文在已有交通脆弱性研究基础上,梳理出目前各类交通脆弱性定义的共同点;基于用户平衡分配模型,给出一种模拟交通网络拥堵传播的级联失效模型,将此模型应用于交通脆弱性评估中;提出交通网络中节点和边脆弱强度的计算公式。以某市子路网为例,计算节点和边的脆弱强度,发现最脆弱的前十个节点和边都分布在主干路。对脆弱强度的敏感性进行分析,发现脆弱强度对于OD需求和通行能力在级联失效临界值附近的变化具有很强的敏感性。结果表明该方法对交通网络中的薄弱单元具有较好的辨识能力。
The transportation network is the basic support for the development of the national economy. The issue of safety and stability in operation has become the focus of attention. In order to identify the weak links in the network, based on the existing research on traffic vulnerability, this paper sorts out the common definitions of all kinds of traffic vulnerability definitions. Based on the user equilibrium allocation model, this paper presents a cascade that simulates traffic jam propagation This model is applied to the assessment of traffic vulnerability. The calculation formula of node and edge fragility in traffic network is proposed. Taking a sub-city network as an example, we calculate the fragility of nodes and edges and find that the top ten nodes and edges that are the most vulnerable are all distributed on the backbone. The sensitivity of fragile intensity is analyzed and it is found that fragility intensity is highly sensitive to the change of OD demand and capacity near the critical value of cascade failure. The results show that this method has better identification ability for the weak elements in the traffic network.