考虑塔梁影响的交叉索多塔斜拉桥中塔抗推刚度估算公式  

Estimation Formula for Longitudinal Restraint Stiffness of the Middle Tower of Multi-tower Cable-stayed Bridge With Crossed Cables by Considering the Effect of Tower and Beam

作　　者：邬晓光[1] 姚丝思 陈恒大 李铸 WU Xiaoguang;YAO Sisi;CHEN Hengda;LI Zhu(Key Laboratory for Bridge and Tunnel of Shaanxi Province,Chang’an University,Xi’an 710064,China;CCCC First Highway Consultants Co.Ltd.,Xi'an 710068,China;Shaanxi Provincial Land Engineering Construction Group,Xi’an 710075,China)

机构地区：[1]长安大学桥梁与隧道陕西省重点实验室,西安710064 [2]中交第一公路勘察设计研究院有限公司,西安710068 [3]陕西省土地工程建设集团,西安710075

出　　处：《北京工业大学学报》2018年第4期577-584,共8页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51308056);陕西省交通运输厅科技资助项目(20130025)

摘　　要：为深入研究交叉索的作用机理,基于变形协调原理,忽略边塔水平小位移,推导了在塔、梁自身刚度影响下,交叉索对多塔斜拉桥中塔约束刚度的估算公式,并进行算例验证.研究结果表明:推导的公式解与有限元解的误差在8%以内,满足斜拉桥概念设计的精度要求.跨中交叉拉索可以使主梁挠度减小,进而提高多塔斜拉桥的整体刚度.多塔斜拉桥整体刚度随交叉索数量的增加而增大,设置10对交叉索后中塔位移减小量高达51%,但刚度增大趋势逐渐减缓.对于交叉索多塔斜拉桥而言,桥塔自身刚度的改变对中塔抗推刚度的影响大于主梁,但二者皆小于跨中交叉索对中塔抗推刚度的影响.With the construction of Queensferry bridge in Scotland,the multi-tower cable-stayed bridges with crossed cables have entered the field of bridge engineers.In order to explore the action mechanism of crossed cables,considering the effect of tower and beam and ignoring the small level displacement of the side tower,based on the principle of deformation coordination,an analytic formula for calculating the longitudinal restraint stiffness of the middle tower of multi-tower cable-stayed bridge with crossed cables was deduced,and a numerical example was carried out.The results show that the error between the formula and finite element is within 8%,and it can meet the requirements of the conceptual design of cable-stayed bridge.Crossed cables can make the beam deflection decrease,thus increasing the overall stiffness of the cable-stayed bridge.The overall stiffness of multi-tower cable-stayed bridge rises as the number of crossed cables increasing.The displacement of middle tower reduction is up to 51%after 10 pairs of crossed cables are set,while the stiffness increase gradually slows down.The change of the stiffness of the tower's effect on longitudinal restraint stiffness of the middle tower for multi-tower cable-stayed bridge is greater than that of the main beam,but the crossed cables play more important roles in increasing the stiffness of the structure.

关 键 词：桥梁工程 多塔斜拉桥 交叉索 中塔抗推刚度 估算公式 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]