新型索拱桥索力与拱轴线双优化实用方法  

Practical method of optimization of cable tensions and arch axis for new type arch bridges with diagonal web cables

作　　者：胡常福[1,2] 郑恒[1] 任伟新[1,3] 上官兴[2] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]华东交通大学土木建筑学院,江西南昌330013 [3]合肥工业大学土木与水利工程学院,安徽合肥230009

出　　处：《中南大学学报（自然科学版）》2014年第7期2320-2325,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51278163);江西省教育厅基金资助项目(GJJ12325);铁路环境振动与噪声教育部工程研究中心资助项目(11TM01)

摘　　要：针对新型索拱桥的特点,提出一种可同时进行索力和拱轴线双优化的方法。基于影响矩阵的原理和迭代法,以弯曲应变能最小为优化目标,提出在抗弯惯性矩无穷小的三铰拱索拱桥有限元模型上,进行拱轴线迭代的实用方法,以同时达到索拱桥的索力调整与拱轴线双优化的目标。以跨径600 m索拱桥作为算例,验证本文方法的有效性及实用方法各参数对结果的影响。研究结果表明:与仅考虑一种优化因素相比,本文方法弯矩分布更合理,弯矩极值约小10%,弯曲应变能约小20%。抗弯惯性矩无穷小模型比抗压刚度无穷大模型能得到更小的弯曲应变能状态;三铰拱模型迭代收敛性能比两铰拱与无铰拱模型的优;索拱桥压力线高次抛物线拟合后的结构内力比低次抛物线结果的优。According to the structure characteristics of a new type arch bridges with diagonal web cables, a practical method of optimization of cable tensions and arch axis was proposed. Based on influence matrix principle, iteration method and minimum bending strain energy, a practical method whose arch axis iteration was done on a three-hinge arch bridge finite element model with almost zero bending moment inertia was proposed for structural optimization including both cable tensions and arch axis. A 600 m span arch bridge with diagonal web cables was used as an example to make the parametric analysis of the proposed method. The results show that the bending moment of proposed method has better distribution along arch span, and has about 10% smaller extreme moment and about 20% smaller bending strain energy than the only one factor considered results. The bending strain energy of finite element model with almost zero bending moment inertia is smaller than that of the finite element model with almost infinity area, and it has better iteration performance of three-hinge arch model than two hinge arch model and hingeless arch model, and it has better structural performance results of high order parabolic than low order parabolic used in pressure line curve fitting.

关 键 词：索拱桥 弯曲应变能 索力调整 最优拱轴线 迭代法 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]