基于猫群算法的重力坝抗滑稳定可靠度分析

Reliability analysis on anti-sliding stability of gravity dams using cat swarm optimization

响应面法是计算重力坝抗滑稳定可靠度的重要方法。针对传统响应面法缺乏参数筛选分析,且缺少利用群体智能算法求解可靠指标研究的不足,提出一种基于猫群算法的加权动态响应面可靠度分析方法,克服经典蒙特卡洛方法需要大量重复抽样的缺点。首先,在考虑坝基岩体渗流应力耦合作用的基础上,采用定量全局敏感性分析方法(EFAST法)筛选基岩参数;其次,通过加权响应面拟合隐式功能函数,同时利用猫群算法求解可靠指标并实现响应面的动态更新;最后,以某重力坝工程为例进行可靠度分析。结果表明,基岩抗剪参数对大坝安全稳定有较大影响,重力坝可靠指标计算结果为2.71,与规范方法结果有显著一致性,所提方法合理可靠,具有较高的实用价值。

The response surface method is in wide use for calculating the reliability of gravity dams against sliding,but traditionally it is short of parameter screening analysis and its previous studies lack calculations of reliability index using an intelligent algorithm.Aiming at the problems,this paper develops a weighted dynamic response surface reliability analysis method using the cat swarm optimization that can overcome the shortcoming of massive repeated sampling in the Monte Carlo method.First,considering the dam foundation seepage-stress coupling,we choose key rock mass parameters through quantitative global sensitivity analysis.Then,the implicit performance function is approximated by a weighted response surface,and dynamic updating along with reliability index calculations is achieved using the cat swarm optimization.Finally,we analyze the sensitivity of dam foundation parameters and its engineering reliability in a case study.The results show that the shear strength parameters of dam foundation have a significant influence on dam stability and the reliability index is 2.71,which agrees well with the calculation results using the standard method.Our new response surface method is effective and reliable and would help further research.