斜拉桥异形钢索塔锚固区受力敏感性因素分析  

Stress Sensitivity Factors in Stay Cable-Pylon Anchorage Zone of an Irregular Cable-Stayed Bridge

作　　者：李健刚 杨冰 LI Jian-gang;YANG Bing(Beijing General Municipal Engineering Design&Research Institute Co.,Ltd.,Beijing 100082,China)

机构地区：[1]北京市市政工程设计研究总院有限公司,北京100082

出　　处：《桥梁建设》2023年第3期64-70,共7页Bridge Construction

基　　金：国家自然科学基金重点国际(地区)合作研究项目(61860206013)。

摘　　要：新首钢大桥主桥为主跨280 m的不对称倾斜拱形钢塔斜拉桥,斜拉索为空间异形索面。由于斜拉索锚固区与变截面扭曲钢塔的空间衔接关系不断变化,导致异形钢索塔锚固区的受力非常复杂。为了解复杂钢索塔锚固区的受力特性,以为该区域局部合理优化提供依据,采用CATIA软件建立索塔锚固区有限元模型,对影响该区域局部受力的主要因素进行敏感性分析。结果表明:影响索塔锚固区的主要敏感性因素包括斜拉索横向偏角、钢锚箱腹板厚度、锚腹板的底部夹角;斜拉索有横向偏角时,锚腹板角点应力对角点约束刚度敏感,且在距离角点4~5 cm处布设加劲肋最为有效;在锚腹板高度一定的前提下,锚腹板与承压板衔接点应力对锚腹板底部夹角较为敏感;锚固区应力扩散区域有限,边、中跨锚固区之间受力相互影响小。The main bridge of Xinshougang Bridge is an asymmetric cable-stayed bridge with a main span of 280 m,featuring its inclined steel arch pylons that create irregular spatial stay cable planes.The stay cables have to be anchored to match the alignment of the twisted steel pylon of varying cross-section,as a result,the load bearing behavior of the anchorage zone of the stay cables in the irregular steel pylon is very complicated.A finite element model of the stay cable-pylon anchorage zone was developed in CATIA software to carry out sensitivity analysis of primary factors concerning the local load bearing condition in the zone,and furthermore,to reveal the load bearing performance of the complicated stay cable-pylon anchorage zone and guide the local load bearing condition optimization of the anchorage zone.The results demonstrate that the primary sensitivity factors in the stay cable-pylon anchorage zone include lateral deflection of the stay cables,thickness of the anchorage webs of steel anchor boxes and the angle between the anchorage webs and the horizontal line.When the stay cables are laterally deflected,the corner stresses of the anchorage plates are sensitive to the corner constraint stiffness,and the most effective way is to place stiffening ribs at a distance of 4 to 5 cm to the corner angle.When the depth of the anchorage webs is constant,the stress in the connection of the anchorage web and load bearing plate is sensitive to the angle between the anchorage web and the horizontal line.The stress diffusion area in the anchorage zone is limited,and the anchorage zones in the side and central spans do not show significant disturbance to each other.

关 键 词：斜拉桥 异形钢索塔 索塔锚固区 受力特性 敏感性因素 有限元法 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]