铅芯橡胶支座在三塔无背索斜拉桥中的应用研究  

Application research on lead rubber bearings in a three-pylon cable-stayed bridge without back stay

作　　者：布占宇[1] 陈剑[2] 

机构地区：[1]宁波大学建筑工程与环境学院,浙江宁波315211 [2]宁波大学建筑设计院有限公司,浙江宁波315211

出　　处：《空间结构》2011年第4期69-75,共7页Spatial Structures

基　　金：浙江省科技厅公益技术研究工业项目(2011C21078);宁波市科技局社会发展科研项目(2011C50017);宁波大学学科项目

摘　　要：某无背索三拱塔斜拉桥跨径组合为30m+60m+70m+80m+40m=280m,中间三个大跨为拱塔斜拉结构,采用拱梁固结、梁墩分离的结构形式,全桥为五跨连续梁体系,斜拉索承担部分桥面恒载和活载,属于部分斜拉桥,约束方式分为普通盆式橡胶支座和铅芯橡胶支座两种.地震反应谱计算结果表明采用普通盆式橡胶支座时,E1概率水平下,桥墩基本都处于弹性状态,E2概率水平下,大部分桥墩都进入了屈服阶段.若把主墩改为铅芯橡胶支座,通过延长结构纵横向振动周期,则既能减小地震内力,又能适当控制上部结构的墩、梁间水平位移,在E1、E2地震作用下各桥墩、桩基础均处于弹性范围,满足规范要求.最后进行了模拟支座非线性特性的时程分析,通过与反应谱法结果相比较,验证计算结果的可靠性.The span makeup of a three-pylon cable-stayed bridge without back stay is 30 meters plus 60 meters plus 70 meters plus 80 meters plus 40meters, which adds up to 280meters in total. The three middle spans are arch pylon cable-stayed bridge. The structural form is pylon-girder fixed and girder-pier separated. The whole bridge is a five span continuous beam system. Partial dead load and live load are carried by stay cables. So the bridge belongs to partial cable-stayed bridge. The constraints include two types, namely pot rubber bearing support and lead rubber bearing support. The calculation results by response spectra analysis show that the bridge primarily stays in elastic condition under the seismic load of E1 level, while most of piers of main bridge come into yielding stage during E2 level earthquake. If lead rubber bearings are used in piers of main bridge, all piers stay in elastic condition under both E1 and E2 level earthquake through elongating structural vibration period, internal seismic force is reduced and the relative displacement between superstructure and the pier is controlled, which makes the design fulfilling the requirement of specifications. Finally the time-history analysis was carried out with nonlinear bearing supports and the results were verified valid through comparing with response spectra calculation results.

关 键 词：斜拉桥 无背索 抗震 铅芯橡胶支座 

分 类 号：U448.27[建筑科学—桥梁与隧道工程]