Unified Recursive Decomposition Algorithm (RDA) For Seismic Reliability Estimation Of Dependent Failure Lifeline Engineering System And Its Application

Lifeline networks refer to the basic engineering facility system that maintain the function of modern city and regional economy and have great influence on national economy and people’s livelihood.A large number of earthquake damage investigations show that the destruction of the lifeline networks will cause serious harm to the social and economic function of the city.Therefore,it is very important to study the seismic reliability estimation of lifeline engineering system.One of the important contents of the seismic reliability estimation of lifeline engineering system is to calculate the connected reliability of lifeline network system under earthquake excitation.The difficulty is how to solve the complexity problem in calculation and analyze the related failure problem of lifeline equipment or structure.Until now,the recursive decomposition algorithm(RDA)of network connectivity reliability analysis has been able to reduce the complexity of network algorithms effectively.However,the existing analytical methods cannot solve the dependency failure problem.In view of this,the seismic reliability estimation of lifeline engineering system considering component dependent failure is studied in this paper.The main contents of this paper are as follows:1.Based on the original RDA,the unified RDA is developed by integrating three parts of the original RDA,which are respectively used for different network weighting forms.2.The SGLD model is used to establish the edge distribution model of extremum response of lifeline equipment or structure.The moment method and the two level method are used to identify the model parameters.3.SCM and Gumbel Copula are used to calculate the joint failure probability of disjoint minimum path and disjoint minimum cut event in RDA respectively and establish the joint distribution model of extremum response of lifeline equipment or structure.Finally,the unified RDA for seismic reliability estimation of dependent failure lifeline engineering system is developed.4.Based on the finite element analysis results of SAP2000,the equivalent single degree of freedom model is used to establish the dynamic model of the equipment.Then,the effective parameters of the oscillators are determined and it can be used to calculate random response samples of the systems.5.By using the established method,the dynamic reliability of primary equipment system in a hypothetical substation is calculated.Based on RDA of network connectivity reliability analysis,SCM and Gumbel Copula are used to calculate the joint failure probability and the unified RDA for seismic reliability estimation of dependent failure lifeline engineering system is developed.Numerical examples show that this method can be used for dynamic seismic reliability estimation of dependent failure lifeline network systems with high accuracy.The research in this paper has important theoretical and practical value for the effective calculation of seismic reliability of dependent failure lifeline engineering systems.