海底管道泄漏风险演化复杂网络分析

为了控制海底管道泄漏连锁风险，基于复杂网络，提出针对管道系统泄漏演化的半定量风险演化评价方法，将复杂的事故风险发展过程转化为简洁的网络分析计算。首先，构建包含30个风险节点与54条连接边的海底管道泄漏演化复杂网络模型；其次，采用无权有向网络中的节点出入度和聚类系数进行风险分析，确定影响管道泄漏的关键节点，提出断链控制方案；最后，将演化模型转化为带权的有向网络，采用Dijkstra算法计算各初始事件导致泄漏事故的最短路径。结果表明:海底管道系统泄漏网络的聚类系数为0.13，网络聚集程度偏低而演化性较强；各初始事件的最短路径均不超过10，表现出明显的小世界网络特征，初始事件的风险经少数几步传递即可导致泄漏事故的发生。海底管道泄漏风险演化规律的研究可为抑制初始事件、控制传递事件和减轻后果事件提供理论依据，对预防海底管道泄漏事故发生、保障管道持续安全运行具有现实意义。

Complex network analysis on risk evolution of submarine pipeline leakage

To control the cascading risk of submarine pipeline leakage, a semi-quantitative assessment method on risk evolution of submarine pipeline system leakage was proposed based on the complex network, so as to convert the complex development process of accident risk into the simple network analysis and calculation. Firstly, a complex network model on evaluation of submarine pipeline leakage was constructed, which included 30 risk nodes and 54 connection edges. Secondly, the risk analysis was carried out by using the out-in degree of nodes and the clustering coefficients in the unweighted and directed network, then the key nodes influencing the pipeline leakage were determined, and the chain breaking control scheme was put forward. Finally, the evaluation model was converted into a directed network with weight, and the shortest paths of each initial event leading to the leakage accident was calculated by using the Dijkstra algorithm. The results showed that the clustering coefficient of the submarine pipeline system leakage network was 0.13, the network aggregation degree was relatively low, while the evolvability was stronger. All the shortest paths of each initial event were no more than 10, which presented the obvious characteristics of small-world network. The risk of initial events would result in the pipeline leakage accident only by the transfer of a few steps. The research can provide the theoretical foundation for the inhibition of initial events, control of transfer events and mitigation of consequential events, and it has practical significance for preventing the leakage accidents and guarding the continuous safety operation of submarine pipeline.