润扬大桥悬索桥长吊索更换技术研究

Replacement Technology of Long Suspenders of Runyang Suspension Bridge

为了对悬索桥服役期间损坏的长吊索进行快速更换,依托润扬大桥南汊悬索桥1对长吊索火灾后紧急更换的工程案例,结合既有吊索锚固构造,设计一种悬索桥长吊索更换装置,开发传统吊索更换须在吊索无应力状态下拆除转换为吊索在有限应力而销轴无应力状态下拆除的吊索更换技术。详细介绍施工过程及施工关键步骤,并采用ANSYS建立全桥有限元模型,对吊索更换过程中的7个关键施工步骤进行仿真模拟,分析更换过程中待更换吊索索力、相邻吊索索力、主缆竖向位移、加劲梁竖向位移等指标的变化趋势。同时,对不中断交通情况下的施工全过程进行监控,实测施工过程中分级张拉临时吊索,安装新吊索、拆除临时索等工况的相应吊索索力以及临时吊索索夹与永久吊索索夹的相对滑移。研究结果表明:实测值与模拟值变化趋势基本吻合,验证了施工方案的合理性;该桥长吊索的成功更换,验证了所开发的吊索更换装置的可靠性,不仅完成了在不中断交通情况下的吊索更换,而且还实现了对悬索桥既有状态干扰最小的目标。

In order to replace the damaged suspender rapidly during the service of the suspension bridges.Based on a case study of a pair of long suspender replacements for the South Branch suspension bridge of the Runyang Bridge after fire,a long suspender replacement system for the suspension bridge was designed,considering the existing suspender anchorage configuration.The traditional suspender replacement technology,which must be removed with the suspender in a non-stress state,is developed to transfer from the suspender being removed in a limited-stress state to the pin shaft of the suspender in a non-stress state.The construction process and key steps were introduced in detail,and ANSYS was used to establish the full bridge finite element model to simulate seven key construction steps in the process of suspender replacement.The change trend of the replaced suspender force,temporary suspender force,adjacent suspender force,and the vertical displacement of the main cable and the stiffening girder during the replacement process are presented.At the same time,the entire construction process without traffic interruption was monitored,and the corresponding suspender force of the graded tension temporary suspender,the installation of the new suspender,the removal of the temporary suspender,and the relative slippage between the temporary suspender clamp and the permanent suspender clamp are recorded.The research results show that the change trend of the actual measured values and the FEM values are basically consistent,which verified the rationality of the construction scheme;The successful replacement of the long suspender verifies the reliability of the suspender replacement device developed in this study.It not only allows suspender replacement without interrupting traffic,but also achieves the goal of minimizing the interference to the existing state of the suspension bridge.