大跨独塔斜拉桥纵向约束体系研究  

Research on Longitudinal Restraint System of Long-span Single-pylon Cable-stayed Bridge

作　　者：叶伟 王雷 段银龙 YE Wei;WANG Lei;DUAN Yinlong(Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou 510507,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广州510507

出　　处：《交通科技》2023年第3期70-74,共5页Transportation Science & Technology

摘　　要：为寻求一种最优纵向抗震体系,以一座位于高烈度区的205 m+205 m独塔斜拉桥为工程背景,建立动力模型进行时程分析,分别从黏滞阻尼器方案和弹性索方案两方面进行参数研究,比选2种方案并确定最优的纵向约束体系。结果表明,在总阻尼力和阻尼指数相同的前提下,当边墩与桥塔的阻尼器屈服力之比为1∶2时,下塔柱底的地震弯矩、塔顶位移与主梁位移均达到极小值;黏滞阻尼器在边墩和桥塔上的布置数量分别为4个、8个,当阻尼指数取0.3、阻尼系数为2000 kN时,地震内力与位移均可得到有效的平衡控制;当全桥2根弹性索刚度为4×104kN/m时,关键截面的弯矩和剪力均出现极小值,黏滞阻尼器方案较弹性索方案的地震内力降幅超过20%,地震位移大致减小50%。In order to find an optimal longitudinal seismic system,a single-pylon cable-stayed bridge with span of 205 m and 205 m,which is located in a high intensity area,is taken as the engineering background,and a dynamic model is established for time history analysis.The parameters of viscous damper scheme and elastic cable scheme are studied respectively,and the two schemes are compared to determine the optimal longitudinal constraint system.The research shows that under the premise of the same total damping force and damping index,when the ratio of the damper yield force between the side pier and the bridge tower is 1∶2,the seismic bending moment at the bottom of the lower tower column,the displacement of the tower top and the displacement of the main beam all reach the minimum value.The number of viscous dampers arranged on side piers and bridge towers is 4 and 8 respectively.When the damping index is 0.3 and the damping coefficient is 2000 kN,the seismic internal force and displacement can be effectively balanced.When the stiffness of the two elastic cables of the whole bridge is 4×104 kN/m,the bending moment and shear force of the key section reach the minimum values.Compared with the elastic cable scheme,the viscous damper scheme reduces the seismic internal force by 20%and the seismic displacement by 50%.

关 键 词：独塔斜拉桥 约束体系 黏滞阻尼器 弹性索 抗震分析 

分 类 号：U441[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]