基于弹性支承连续梁法的混凝土斜拉桥合理成桥索力计算方法  

Method to Calculate Stay Cable Forces of Concrete Cable-Stayed Bridge After Completion Based on Elastically Supported Continuous Girder Method

作　　者：付春雨 高振锋 严鹏 唐重平 唐波 FU Chun-yu;GAO Zhen-feng;YAN Peng;TANG Zhong-ping;TANG Bo(College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;China SWJTU Railway Development Co.,Ltd.,Chengdu 610073,China;China Railway Guangzhou Group Co.,Ltd.,Guangzhou 510080,China)

机构地区：[1]河海大学土木与交通工程学院,江苏南京210098 [2]四川西南交大铁路发展股份有限公司,四川成都610073 [3]中国铁路广州局集团有限公司,广东广州510080

出　　处：《桥梁建设》2022年第6期124-130,共7页Bridge Construction

基　　金：中国国家铁路集团有限公司科技研究开发计划课题(N2019G059)。

摘　　要：为准确方便地确定混凝土斜拉桥的合理成桥索力,利用结构弯曲应变能最小化原则,将斜拉索视为弹性支承,将主梁和桥塔均视为弹性支承连续梁,提出一种基于弹性支承连续梁模型的混凝土斜拉桥合理成桥索力计算方法。该方法首先计算恒载作用下主梁的弹性支承力,作为斜拉索的竖向分力,求得斜拉索的合理成桥状态索力初始值,再根据塔偏变形引起的索力变化修正索力初始值最终得到合理成桥索力。以增江特大桥为工程背景,采用本文方法计算合理成桥索力及在该索力下的主梁弯矩、应力、结构位移等成桥结构响应。结果表明:所计算出的成桥索力中,恒载作用下主梁支承力产生的索力初始值占比大,而塔偏修正值占比小;该索力能够使混凝土斜拉桥结构达到合理成桥状态,同时其计算过程简化,计算量小,可为混凝土斜拉桥合理成桥索力计算提供一种新思路。In this paper,a method to calculate the rational stay cable forces of concrete cable-stayed bridges after completion is proposed.The method is based on the elastically supported continuous girder model,which can generate accurate results and facilitate the calculation process.By using the method,the stay cables are viewed as elastic supports and the main girder and pylons as the elastically supported continuous girder,following the minimization principle of structural bending strain energy.First,the elastic supporting forces of the main girder under dead loads are derived and taken as the vertical component of the stay cable force to obtain the initial stay cable forces in the rational bridge completion state.Then,the stay cable force fluctuation caused by the pylon deformation is used to modify the initial stay cable forces to gain the rational stay cable forces after the completion of the bridge.The proposed method has been employed in the Zengjiang River Bridge.The rational stay cable forces of the bridge after completion as well as the structural responses of the completed bridge,including the bending moment,stresses,and displacement of the main girder were calculated.The engineering application indicates that among the calculated stay cable forces in the bridge completion state,the initial stay cable forces induced by the supporting forces of main girder under dead loads account for a large portion,while that caused by the pylon deformation modification is relatively smaller.The stay cable forces permit the concrete cable-stayed bridge to reach the rational completion state.Furthermore,the simplified calculation process and smaller calculation amount makes it a new option to calculate the rational stay cable forces of concrete cable-stayed bridge after completion.

关 键 词：混凝土斜拉桥 弹性支承连续梁 弯曲应变能最小化 成桥索力 合理成桥状态 主梁变形 塔偏 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] U441.4