斜拉桥索塔分组集聚锚固体系设计探讨  

Discussion on Design of Cable Pylon Grouping-anchorage-system of Cable-stayed Bridge

作　　者：李茜[1] 左新黛[1] 文坡[2] LI Qian;ZUO Xin-dai;WEN Po(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan Hubei 430056,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]中铁大桥勘测设计院集团有限公司,湖北武汉430056

出　　处：《公路交通科技》2021年第4期55-62,共8页Journal of Highway and Transportation Research and Development

基　　金：公路院科技创新专项资金项目(2019-I113)。

摘　　要：斜拉桥索塔分组集聚锚固体系是一种新型的锚固体系,它将斜拉索分组锚固于塔柱间钢箱梁横隔板之间的锚固构造内,形成索塔体外锚固体系。与传统的索塔锚固方式相比,混凝土与钢横梁承压板连接部位始终处于受压状态,降低塔柱混凝土开裂的风险,并可实现塔梁同步施工,施工便捷性和经济性均有优势。国内安徽池州大桥首次成功应用此新型锚固体系。为明确分组集聚锚固体系的力学行为特性和设计方法,以池州大桥为例,首先介绍了该体系的基本设计思想,从斜拉索分组原则、钢横梁设计要点、塔梁连接构造设计几个方面进行了阐述。接着应用有限元软件Midas建立全桥仿真模型,设计了6种计算工况,对斜拉索索面布置、分组集聚形式、钢横梁设计参数进行了敏感性分析。引入塔梁刚度比,研究主塔与钢横梁的刚度匹配,明确了分组、集聚、塔梁刚度比对全桥受力的影响,并给出了设计优化建议。结果表明:分组集聚锚固体系对全桥的横向稳定性和抗扭转性能更有利,钢横梁受力较为复杂,是今后设计的重点;改变横梁长度带来的是主塔-横梁局部受力的变化,改变横梁间距带来的是斜拉桥整体受力的变化;在满足布设空间和构造要求前提下,尽可能减小钢横梁长度和增大横梁间距,以减小塔梁刚度比、提高斜拉索效率,对索塔体系受力和经济性均有利。Cable pylon grouping-anchorage-system of cable-stayed bridge is a new type of anchorage system,which anchors grouping stay cables in the anchoring structure between the steel box girder diaphragms between the pylon columns to form the external anchorage system of the cable pylon.Compared with the traditional pylon anchorages,this system makes the joint part of concrete and steel beam bearing plate under pressure to reduce the risk of concrete cracking of the columns,it can also realize the synchronous construction of pylon and beams,and has advantages in construction convenience and economy.The new anchorage system is successfully applied to Chizhou Bridge in Anhui Province for the first time.In order to make clear the mechanical behavior characteristics and design method of the grouping-anchorage-system,taking Chizhou Bridge for example,the basic design idea of the system is introduced at first,and the grouping principle of stay cables,the design points of steel beams and the design of the pylon beam connection are expounded.Then,the simulation model of the bridge is established by using Midas software,and 6 calculation conditions are designed to analyze the sensitivity of cable plane layout,grouping form and steel beam design parameters.Afterwards,by introducing the pylon-beam stiffness ratio,the stiffness matching between main pylon and steel beams is studied,the influence of grouping,agglomeration and pylon-beam stiffness ratio on the stresses of the bridge is clarified,and the design optimization suggestions are given.The result shows that(1)the grouping-anchorage-system is more favorable to the lateral stability and torsion resistance of the whole bridge,the stresses of the steel beams are more complex,which is the focus of the future design;(2)changing the length of the steel beam will bring about the stress changes in the local stress of pylon-beam,and changing the space between steel beams will bring about the stress changes in the whole bridge;(3)on the premise of meeting the layout space and structural

关 键 词：桥梁工程 斜拉桥 分组集聚 锚固体系 设计敏感性分析 有限元 塔梁刚度比 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]