基于Copula理论的高桩码头岸坡可靠性分析

Reliability Analysis of Piled Wharf and Bank Slope Based on Copula Theory

高桩码头岸坡稳定性对整体码头结构安全至关重要。为进一步探究高桩码头岸坡土体强度参数相关性及空间变异性对高桩码头岸坡可靠性的影响规律,基于Copula理论考虑岸坡土体参数的联合概率分布特性,采用PLAXIS计算平台建立高桩码头-岸坡体系数值计算模型,进一步通过Python API接口,编译完成了可自动数据交互与求解的外挂子程序SAPW,并实现了高桩码头岸坡体系参数化前处理、样本工况计算和可靠性求解的一体化、全链条可靠性分析框架流程,并在此基础之上结合蒙特卡罗模拟方法,开展了相关数值计算与参数化分析,探讨了黏聚力、内摩擦角变异系数以及二者相关系数对高桩码头岸坡可靠性的影响规律。结果表明:在高桩码头设计与分析中,忽略土体参数相关性和空间变异性会高估岸坡失效概率,进而导致相关可靠度分析偏于保守,在高桩码头岸坡可靠度分析中宜采用多种Copula函数进行综合考虑。

The stability of bank slopes in a piled wharf is critical for the overall safety of the wharf structure.In order to further investigate the influence of the correlation and spatial variability of soil strength parameters on the reliability of piled wharf bank slopes,this paper employed Copula theory to analyze the joint probability distribution characteristics of bank slope soil parameters.Utilizing the PLAXIS computational platform,a numerical model of piled wharf-slope system was established.Ad-ditionally,an auxiliary subroutine named SAPW was developed via Python API interface to facilitate automatic data exchange and solution computation.This integrated,end-to-end reliability analysis framework encompassed pre-processing of parameters,calculation of sample conditions and reliability solving for the high-pile wharf-slope system.Furthermore,Monte Carlo simulation methods were used to conduct related numerical computations and parameterized analyses,investigating the impact of cohesion,internal friction angle variability,and their correlation coefficients on the reliability of piled wharf bank slopes.The results show that neglecting the correlation and spatial variability of soil parameters in the design and analysis of piled wharfs can overestimate the probability of bank slope fail-ure.This,in turn,leads to a conservative bias in related reliability analyses.Therefore,it is advisable to employ various Copula functions for comprehensive consideration in the reliability analysis of piled wharf bank slopes.