基于一阶优化法的拱桥预拱度设置方法研究  

Research on the precamber settingmethod of arch bridge based on first-order optimization method

作　　者：张睿 陈建明 Zhang Rui;Chen Jianming(Anhui Expressway Engineering Test and Research Center Co.,Ltd.,Hefei Anhui 230601,China)

机构地区：[1]安徽省高速公路试验检测科研中心有限公司,安徽合肥230601

出　　处：《山西建筑》2025年第9期174-178,共5页Shanxi Architecture

摘　　要：拱桥通过有限元仿真计算的方法设置预拱度,受活载的影响,拱肋与主梁的预拱度线形呈现“双波峰”形态。为改善拱肋与主梁的预拱度线形的平顺性,提出了一种基于一阶优化法的拱桥合理预拱度设置方法。该方法首先通过待定系数的多项式拟合活载预拱度曲线,再利用MATLAB程序求解目标函数以获得多项式系数。为验证该方法的有效性,以某钢箱提篮拱桥为背景,采用该方法计算拱肋与主梁的预拱度。以优化后的预拱度与有限元仿真计算预拱度的差值最小为优化目标,以多项式系数为优化变量,以拱脚处预拱度为零以及优化后的拱肋预拱度值大于有限元仿真计算预拱度值为约束条件,建立了目标函数进行优化。结果表明,该优化方法能有效解决基于有限元仿真计算得到的拱肋及主梁预拱度线形平顺性不佳的问题。The precamber of the arch bridge is set by finite element simulation calculation,and the precamber alignment of the arch rib and the main beam presents a“double peak”shape under the influence of live load.In order to improve the smoothness of the precamber alignment between the arch rib and the main beam,a reasonable precamber setting method of arch bridge based on the first-order optimization method was proposed.In this method,the live-load precamber curve is first fitted by the polynomial of the coefficients to be determined,and then the objective function is solved by using the MATLAB program to obtain the polynomial coefficients.In order to verify the effectiveness of the method,the method is used to calculate the precamber degree of the arch rib and the main beam with a steel box basket arch bridge as the background.The objective function was established to optimize the optimization by taking the minimum difference between the optimized precamber and the finite element simulation as the optimization goal,the polynomial coefficient as the optimization variable,and the precamber at the arch foot being zero and the optimized arch rib precamber value being greater than the finite element simulation calculating the precamber value as the constraints.The results show that the proposed optimization method can effectively solve the problem of poor linear smoothness of arch rib and main camber precamber calculated based on finite element simulation.

关 键 词：拱桥 有限元仿真 预拱度 目标函数 一阶优化法 

分 类 号：TU997[建筑科学—市政工程] U448.22[建筑科学—桥梁与隧道工程]