大跨度非对称拱桥结构合理拱轴线形研究  

Study on Reasonable Arch Axis Shape of Long Span Asymmetric Arch Bridge

作　　者：李振东 LI Zhendong(China Railway Siyuan Survey and Design Group Co.,Ltd.,Wuhan 430063,China;China Railway Construction Bridge Design and Research Branch,Wuhan 430063,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,湖北武汉430063 [2]中铁建大桥设计研究院,湖北武汉430063

出　　处：《甘肃科学学报》2022年第4期98-106,共9页Journal of Gansu Sciences

基　　金：中铁第四勘察设计院集团有限公司科技研发项目(2020K002)。

摘　　要：非对称拱桥因其合理的拱轴线、灵活的拱脚位置和桥面纵坡,能够更好地适应起伏较大的山区地形,使拱桥跨径选择更合理\,更经济\,更美观。主拱圈作为拱桥的主要承重结构,其拱轴线形直接影响拱肋截面内力的分布和大小。因此,确定大跨度非对称拱桥线形是拱桥设计的重要内容。通过理论推导非对称拱桥的合理拱轴线方程,提出了一种基于弯曲变形能最小和惩罚函数思想的拱轴线形优化方法,该方法考虑了全拱肋的受力状态,充分发挥了材料的性能,并兼顾了桥梁造型和施工便捷性。研究以某大跨度铁路非对称拱桥为工程背景,通过遗传算法(GA)和有限元法搭建了MATLAB-ANSYS联合仿真程序,吸纳了GA全局搜索能力强的特点,方便快捷地确定了其最佳的拱轴线形,验证了采用该方法优化拱轴线形的可行性和实用性;最后对结构参数的敏感性进行分析,探究了结构参数对拱肋受力的影响。研究为大跨度非对称拱桥结构合理拱轴线形的确定提供了一种便捷有效的解决方案,提高了设计效率,为结构优化设计提供了新的思路。Asymmetric arch bridge with its reasonable arch axis,flexible arch foot position and longitudinal slope of bridge deck can better adapt to the undulating mountainous topography,so that the arch bridge span selection is more reasonable,economical and handsome.As the main load-bearing structure of arch bridge,the arch axis shape of arch ring directly affects the distribution and size of internal force of arch rib section.Therefore,determining the alignment of long-span asymmetric arch bridge is an important part of arch bridge design.In this paper,the reasonable arch axis equation of asymmetric arch bridge is theoretically deduced,and an optimization method of arch axis shape based on the idea of minimum bending deformation energy and penalty function is proposed.The stress state of the whole arch rib is considered in this method,which gives full play to the performance of the material,and takes into account the bridge modeling and construction convenience.With a long-span railway asymmetric arch bridge as the engineering background,the MATLAB-ANSYS co-simulation program was established by using genetic algorithm(GA)and finite-element method,which absorbs the strong global search ability of GA,and determines the optimal arch axis shape conveniently and efficiently.The feasibility and practicability of this method to optimize the arch axis shape were verified.Finally,the sensitivity of structural parameters is analyzed to explore the influence of structural parameters on the force of arch ribs.According to the research in this paper,a convenient and effective scheme is provided for the determination of the reasonable arch axis of the large-span asymmetric arch bridge structure,which improves the design efficiency and provides a new idea for the structural optimization design.

关 键 词：非对称拱桥 合理拱轴线 线形优化 惩罚函数 敏感性分析 

分 类 号：U24[交通运输工程—道路与铁道工程] O342[理学—固体力学]