竖向荷载下基桩可靠度优化设计方法研究  

Study on reliability optimization design method of piles under vertical loads

作　　者：徐志军[1] 韩星 郑俊杰[2] 原方[1] XU Zhijun;HAN Xing;ZHENG Junjie;YUAN Fang(School of Civil Engineering and Architecture,Henan University of Technology,Zhengzhou 450001,China;School of Civil Engineering and Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]河南工业大学土木建筑学院,河南郑州450001 [2]华中科技大学土木工程与力学学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2020年第5期55-60,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51608177,51978247);国家重点研究发展计划资助项目(2016YFC0800200)。

摘　　要：为解决繁琐的计算制约着可靠度优化设计方法应用于桩基工程这一问题,分析了竖向荷载下基桩的破坏模式,利用可靠度理论和优化设计方法建立了可靠度优化设计模型.基于中心点法,提出了一种改进的可靠度优化计算方法,用以解决可靠度优化计算中产生的非线性迭代繁琐过程.建立了可靠度指标的修正函数以提高计算精度,并利用线性回归方法给出了修正函数的计算方法.实例分析结果表明:改进的可靠度优化方法在提高计算效率的同时也保证了计算精度;局部优化和全局优化后的目标函数值分别减小了20.2%和24.9%,较大程度地降低了施工成本.To solve the problem that unbearable computation cost is the barrier for the application of reliability optimization design method in pile foundation engineering,the failure model of piles under vertical load was analyzed,and the reliability optimization design model was proposed based on reliability theory and optimization design method.In order to solve the problems caused by the cumbersome process during reliability optimization calculation,a modified optimization calculation method was proposed.To update the computational accuracy,a revised function of reliability index was given,and linear regression was employed to calculate revised function.Results from case study show that the modified optimization calculation method not only can improve the computational efficiency,but also improve the computational accuracy.Through local optimization and global optimization,the objective function values are reduced by 20.2%and 24.9%,respectively,which lowers the construction cost.

关 键 词：基桩 可靠度优化设计 竖向荷载 目标函数 非线性迭代 

分 类 号：TU473.1[建筑科学—结构工程]