大跨度公铁同层斜拉桥锚箱式索梁锚固结构传力机理及参数分析  

Load Transfer Mechanism and Parameter Analysis of Anchor Box Type Cable-girder Anchorage for Long-span Cable-stayed Bridge with Deck Accommodating Both Highway and Railway Traffic

作　　者：洪彧[1] 周文钦 龚顺攀 蒲黔辉[1] 郭忠义 HONG Yu;ZHOU Wenqin;GONG Shunpan;PU Qianhui;GUO Zhongyi(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《铁道学报》2023年第6期142-150,共9页Journal of the China Railway Society

基　　金：广西创新驱动发展专项资金(桂科AA21077011);四川省科技计划(2021YJ0054,2022JDRC0012)。

摘　　要：鉴于锚箱式索梁锚固结构构造和受力复杂,以某在建四塔大挑臂公铁同层斜拉桥锚箱式索梁锚固结构为研究对象,采用数值模拟分析该结构在设计索力作用下应力分布规律及荷载传递机理,通过参数分析研究合理的结构设计参数。研究结果表明,该桥索梁锚固结构各受力板件均存在不同程度的应力集中,应力集中主要出现在板件开孔边缘以及板件间交界处;锚固结构通过支承板与主梁腹板间4条连接焊缝以剪力的形式传递92.5%的索力,索力传递效率较传统钢锚箱更高;锚固结构中,各受力板件厚度变化对各板件力学行为影响具有耦合性,封端板和支承板受力对其自身厚度变化最为敏感,且封端板和支承板厚度增加能够缓解各板件的应力集中,但2片外侧加劲板对锚固结构各板件受力影响很小。建议该类型索梁锚固结构在保留封端板和支承板原设计的基础上去除两侧加劲板,将更具经济性。In response to the complex structural form and force of the anchor box-type cable-girder anchorage structure,in the case of the anchor box-type cable-girder anchorage structure of an under-construction four-tower large-cantilever cable-stayed bridge with deck accommodating both highway and railway traffic,numerical simulation was used to analyze the stress distribution law and load transfer mechanism under the design cable force,and the reasonable structural design parameters were studied through parameter analysis.The results show that different degrees of stress concentration exist in each stressed plate of the cable-girder anchoring structure of the bridge,and the stress concentration mainly occurs at the edge of the opening of the plate and the junction between the plates.The four connecting welds between the supporting plates and the beam webs transmit 92.5[WTB4]%[WTBZ]of the cable force in the form of shear force,with higher cable force transmission efficiency than that of the traditional steel anchor box.The changes in the thickness of the stressed plates in the anchorage structure have a coupling effect on the mechanical behavior of each plate.The force of the endplate and the support plate is most sensitive to the change of their thickness,and the increase of the thickness of the endplate and the support plate can alleviate the stress concentration of each plate,but the two outer stiffening plates have minor influence on the force of each plate of the anchorage structure.This paper proposes that this type of cable-beam anchorage structure should remove the stiffening plates on both sides based on retaining the original design of the endplate and the support plate,to have a better economy.

关 键 词：公铁同层斜拉桥 索梁锚固结构 有限元分析 传力机理 参数分析 结构优化 

分 类 号：U448.[建筑科学—桥梁与隧道工程]