Risk Minimization Research Of Urban Lifeline System Cascading Failure

Urban Lifeline System is the central nervous system of city to ensure a normal life and production usually including urban transport, energy, telecommunications, water supply and drainage systems in urban infrastructure. Water supply system is an important part of the urban lifeline systems, it is the basic industry of urban life and national economy being an important guarantee for social and economic development.The occurrence of natural disasters threatened the survival of the human condition, after the disaster, the service capabilities of city water supply, electricity, communications, transportation, gas and other parts of the system or a complete would be failure. It will lead to secondary disasters making the whole city into a crash because of the relevancy between with the various systems working independently. Over the years, natural disasters caused direct losses and indirect losses more significant, research to minimize the risk of lifeline systems cascade failure were more important. In disasters, the failure mode of Water Distribution System is the destruction of some nodes in the network often leads to the cascading failure of the entire network. Cascading failure phenomenon expands the destruction impact scope and degree of the water distribution system. Research of minimization lifeline system cascading failure risk has practical application value and significance. Therefore discussion has been carrying out in the following:The article put forward the concept of cascading failure risk of water supply network based on the review of domestic and foreign lifeline engineering research on the history and current situation. Realization the information entropy index and internal redundant evaluate the reliable of water supply network. Traffic entropy models can be integrated into the Optimization calculation in order to improve water supply network reliability and reduce the occurrence of cascading failures.The article made network delay simulation analysis using EPANET in order to make the network more realistic. The flow was obtained each time period of each tube segment to analyze the Cascading failure risk of water supply network. Calculating cascading failure risk value of water supply network of each period further illustrated the feasibility and necessity of risk optimization of water supply network.Establishment cascade failure risk optimization model of water supply network. Process using MATLAB genetic algorithm was applied to achieve computation model by coding designed, determined the adaptation function, set genetic operators and parameters. Analyze and demonstrate the algorithm calculation procedures through a pipe network case.Identify the key network nodes under consideration of secondary damage risk. Based on set pair analysis theory, analysis water distribution system development trend after the first destruction and effect of failure nodes on other nodes in network ranks the importance of nodes in water distribution system by calculating the set pair potential. This evaluation of nodal importance considering the system development trend provides a fundamental basis for reducing the risk of cascading failures of the whole system...