基于概率的退化钢筋混凝土桥梁加固措施优化

Probabilistic based Optimization of Maintenance Actions for Deteriorating RC Bridges

摘要:

提出了一种基于概率的退化钢筋混凝土桥梁加固措施优化分析方法.选取构件可靠度作为性能指标,通过寿命函数来衡量结构性能演变过程,利用结合拉丁超立方抽样和计算机程序CBDAS的蒙特卡洛模拟法求解不同时刻的可靠度,再通过曲线拟合得到相应的寿命函数;给出加固措施对寿命函数影响的数学模型;建立了加固措施优化分析方法,根据可能的维修方案先将初始优化问题划分为一组局部优化问题,再利用遗传算法求出每个局部优化问题的最优解集,通过比较不同局部优化问题的最优解集可找出针对任意特定条件的最佳解.最终,将建立的优化方法应用到一座位于上海地区的三跨钢筋混凝土桥梁.

Abstract:

A novelmaintenanceoptimization approach under uncertainty is proposed for deteriorating reinforced concrete (RC) bridges.The component reliability is used as performance indicator and the structure performance is modeled by using lifetime function.Firstly,the lifetime function is fitted by using a group of pointintime component reliabilities evaluated by Monte Carlo simulations,associated with Latin hypercube sampling and the computer program CBDAS.Secondly,models that reflect the effects of maintenance types on the lifetime functions are presented.Finally,a novel approach for optimization of maintenance is proposed.The original optimization problem is firstly divided into a set of suboptimization problems based on possible maintenance scenarios.Then the optimal solutions of each suboptimization problem are sought in terms of genetic algorithm.Thus,the best solution with respect to any specified condition can be found out by comparing the optimal solutions of the suboptimization problems.The optimization approach is applied to a threespan RC bridge in Shanghai.