强震下多跨连续隔震坡桥非线性地震响应分析  

Nonlinear seismic response analysis of multi-span continuous isolation slope bridge under strong earthquakes

作　　者：孙昱坤 黄襄云[1,2] 刘彦辉[1,2] 周露 SUN Yu-kun;HUANG Xiang-yun;LIU Yan-hui;ZHOU Lu(Earthquake Engineering Research&Test Center,Guangzhou University,Guangzhou 510006,China;Guangdong Provincial Key Laboratory of Earthquake Engineering and Applied Technology/Key Laboratory of Earthquake Resistance,Earthquake Mitigation and Structural Safety,Ministry of Education,Guangzhou 510006,China)

机构地区：[1]广州大学工程抗震研究中心,广东广州510006 [2]广东省地震工程与应用技术重点实验室/工程抗震减震与结构安全教育部重点实验室,广东广州510006

出　　处：《广州大学学报（自然科学版）》2023年第2期16-24,共9页Journal of Guangzhou University:Natural Science Edition

基　　金：国家重点研发计划重点专项资助项目(2019YFEO112500)。

摘　　要：跨海工程中,常采用高、矮墩并存的连续坡桥连接主航道桥与非通航孔桥,墩高的差异导致各墩变形不一致,上部结构惯性力不均匀分布于各墩柱。为探究采用隔震技术时连续坡桥各墩柱的纵向动力响应和失效模式,以某跨海工程中的连续坡桥为例,考虑桥墩材料非线性的影响,在墩、梁连接处设置摩擦摆支座建立桥梁隔震体系,采用曲率延性系数及支座极限容许位移作为桥梁损伤指标,量化坡桥在强震下采用隔震与非隔震体系的抗震性能。结果表明:隔震坡桥与非隔震坡桥相比,基本周期明显延长,隔震坡桥的动力特性与隔震平桥的动力特性基本相近,振型以主梁位移为主,桥墩弯曲变形较小;隔震坡桥的动力响应幅值显著减少,明显改善了高、矮墩惯性力不均衡分布,但其动力响应幅值还是受墩高变化的影响存在一定差异;强震作用下,非隔震坡桥的墩柱先于支座且矮墩先于高墩发生损伤,隔震坡桥的破坏状态与隔震平桥一致,其墩柱及隔震支座均未发生破坏。In cross-sea projects,continuous girder bridges with coexisting high and short piers are usually used to connect the main navigation channel bridge with the non-navigable span bridge.The difference in height of each pier not only leads to inconsistent deformation of each pier,but also uneven distribution of inertia forces generated by the superstructure on each pier.In pursuit of investigating the longitudinal dynamic response and damage modes of each pier column of isolated continuous slope bridges,a continuous slope bridge in a cross-sea project is taken as an example.The effect of material non-linearity on the bridge pier is considered.Friction pendulum bearings are provided at the pier and girder joints to establish an isolated system.The curvature ductility and the ultimate allowable displacement of the bearings were used as damage indicators to quantify the seismic performance of the slope bridge with and without seismic isolation systems under macroseism.The results show that:compared with non-isolated slope bridges,the fundamental period of isolated slope bridges increases,the natural vibration characteristics of isolated slope bridges are basically similar to those of isolated flat bridges,the vibration modes are dominated by the displacement of the main girder and the bending deformation of the pier is small;the amplitude of the dynamic response of the isolated slope bridge is significantly reduced,and the unbalanced distribution of inertia forces caused by the coexistence of high and short piers is significantly improved,but there are still some differences in the amplitude of the dynamic response of each pier column due to the change of pier height;when the bridge is subjected to macroseism,the pier of the non-isolated slope bridge is damaged before the bearing and the short pier is damaged before the high pier,while the damage state of the isolated slope bridge subjected to macroseism is the same as that of the isolated flat bridge,and their piers and isolation bearings are not damaged.

关 键 词：隔震连续梁桥 坡桥 材料非线性 抗震性能 破坏模式 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]