整束挤压式吊杆安装及张拉施工关键技术

阜阳市向阳路颍河大桥主桥为(47+148+47) m三跨下承式梁拱组合体系钢结构拱桥。全桥共设吊杆42根,采用钢绞线整束挤压可更换成品吊杆体系。为安全、高效地完成吊杆安装,研发了一种拱桥柔性吊杆高空安装操作平台,借助起吊设备能高效精确地将吊杆固定端叉耳与拱圈耳板对接。为最大限度减少吊杆张拉对桥梁结构内力及线形的影响,针对整束挤压式吊杆构造特点,研发双顶对称同轴专用张拉工装与之配套施工,对纵横桥向同一编号的4根吊杆同步进行张拉。通过MIDAS/Civil程序对不同张拉工况进行有限元分析,确定合理的张拉顺序,减少了吊杆索力调整次数。通过施工实践及监控实测表明:吊杆安装及张拉方法在技术上是可行的,吊杆张拉顺序是合理的。

Key Technologies of Installation and Tension Construction for Whole Bundle Extrusion Suspender

The main bridge of Yinghe bridge on Xiangyang road in Fuyang city is a steel structure arch bridge with (47+148+47)m three-span through beam-arch composite system.There are forty-two suspenders in the whole bridge,and the whole steel strand extrusion replaceable f inished suspender system was adopted.In order to complete the installation of suspenders safely and eff iciently,an aerial installation platform for f lexible suspenders of arch bridges was developed. W ith the help of crane equipment,the f ixed end of the suspender fork ear can be eff iciently and accurately butted with the arch ring ear plate.In order to minimize the inf luence of suspender tension on the internal force and alignment of bridge structure,according to the structural characteristics of the whole bundle extrusion suspenders,a special double-top symmetrical coaxial tensioning tooling was developed to construct the bridge,and four suspenders with the same number were tensioned synchronously along the longitudinal and transverse directions of the bridge.The different tensioning conditions were carried out through the MIDAS/Civil program.The reasonable tension sequence was determined,which reduces the adjustment number of suspender cable force.The construction practice and monitoring measurement show that the installation and tension methods of suspenders are technically feasible and the tension sequence of suspenders is reasonable.