针对传统概率可靠性分析方法在重力坝可靠性分析方面因结构自身性能不确定性及功能函数高度非线性等影响，其解析过程中收敛性差、精度低且耗时较长等问题，结合改进粒子群算法（particle swarm optimization,PSO）、Kriging模型提出一种基于IPSOKriging模型的重力坝可靠性分析方法。借助PSO全局寻优能力强和鲁棒性强等优点，通过对算法本身加以变异操作、惯性权重和高斯加权等诸多方面进行重构（improved PSO,IPSO），依靠IPSO算法的群体搜索能力克服模式搜索法寻得参数θ*易陷入局部最优值和对初始值较敏感的缺点，确保在任意初始值条件下都能获得极大似然条件下搜索到的最优参数θ*，进而改善传统PSO收敛速度慢和早熟等问题。通过构建融合IPSO算法IPSO-Kriging数学模型，建立基于IPSO-Kriging模型的重力坝可靠性优化模型。经实例考证所建方法既能合理考量参数变异性，又能在提升精度基础上减少仿真计算次数以实现重力坝工程可靠性的高效计算。
Aiming at the reliability analysis of gravity dams by traditional probabilistic reliability analysis methods,the analysis process has poor convergence,low accuracy,and long time consumption due to the influence of the structural performance uncertainty and the high nonlinearity of the function.Combined with improved particle swarm optimization (IPSO) and the Kriging model,a reliability analysis method of gravity dam based on the IPSO-Kriging model is proposed.The particle swarm optimization (PSO) algorithm is reconstructed employing mutation operation,inertial weight,and Gaussian weight,to improve the traditional PSO algorithm′s slow convergence speed and early maturity.The IPSO and Kriging model are integrated to establish the reliability optimization model of gravity dam based on the IPSO-Kriging model. Under the synergistic action of many factors,such as static and dynamic load,bad environment,and aging of materials,the functional function of a gravity dam is often highly nonlinear,which is difficult to be described by an explicit mathematical model.This leads to the limitation of the traditional analysis method in the process of gravity dam engineering reliability.To break through the constraints of highly nonlinear and non-dominant structural function,it is intended to explore a reasonable optimization scheme based on the basic principle of the Kriging model to make it have higher fitting ability and robustness,to achieve accurate and efficient calculation of reliability of complex gravity dam engineering. Considering the traditional Kriging model,the pattern search method has poor global optimization ability and is sensitive to the initial value.The PSO algorithm is adopted and variation operation,inertial weight,and Gaussian weight are implemented to improve the algorithm.On this basis,the IPSO algorithm is used to optimize the Kriging model to overcome the defects of the pattern search method and build the IPSO-Kriging model with stronger and stable predictive ability.Finally,on the premise of explicit numerical examples to verify the accuracy and efficiency of the established method,the ABAQUS simulation software and Matlab implementation program are used in combination with the actual engineering to realize the efficient calculation of gravity dam reliability. Based on the actual gravity dam engineering,considering the highly nonlinear and nondominant characteristics of gravity dam function,the constructed IPSO-Kriging model and the reliability index optimization calculation method are applied to realize the efficient calculation of the reliability index of gravity dam.This is mainly attributed to the following unique advantages of the IPSO-Kriging model in reliability analysis of complex structural engineering with high nonlinear degree:(1) The variation operation,inertial weight,and Gaussian weight of PSO algorithm are improved and introduced into the Kriging model.An IPSO algorithm based optimization Kriging model is proposed,which could effectively solve the problems of the local optimal solution and difficult initial value selection in the traditional Kriging model.(2) The reliability index optimization calculation model is established based on the organic combination of reliability index definition and optimization algorithm,and the reliability index optimization design method of a gravity dam is proposed based on the IPSO-Kriging model.The method presented can improve the calculation accuracy and reduce the number of simulations to save the calculation cost.(3) Based on the advantages of the established IPSO-Kriging model and the high efficiency of the proposed method,the finite element model of structural limit state reliability is built with the help of the advantages of the finite element simulation platform,and the corresponding implementation program is developed.Compared with other methods,this method has higher calculation accuracy and efficiency,and good adaptability and robustness.