自锚式悬索桥地锚转自锚体系转换分析  

Ground-anchor to Self-anchor System Transformation Analysis for Self-anchored Suspension Bridge

作　　者：黄甘乐 郑建新[1,2,3] 孙南昌 HUANG Gan-le;ZHENG Jian-xin;SUN Nan-chang(CCCC Second Harbor Engineering Co.,Ltd.,Wuhan,Hubei 430040 China;Key Laboratory of Long-span Bridge Construction Technology,Wuhan,Hubei 430040 China;CCCC Highway Bridge National Engineering Research Centre Co.,Ltd.,Beijing 100000,China)

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040 [2]长大桥梁建设施工技术交通行业重点实验室,湖北武汉430040 [3]中交公路长大桥建设国家工程研究中心有限公司,北京100000

出　　处：《公路交通科技》2024年第11期143-150,共8页Journal of Highway and Transportation Research and Development

基　　金：中国交通建设股份有限公司科技研发项目(2022-ZJKJ-01)。

摘　　要：为研究自锚式悬索桥在“先缆后梁”施工中采用临时地锚时的结构受力及变形特性,以东莞沙田大桥为工程背景,建立从地锚转换为自锚的有限元模型。分析了临时拉索同步释放、两岸交替释放、循环释放3种体系转换过程的吊索、梁、塔的应力及变形;对比了体系转换过程中的索鞍抗滑移安全系数变化规律。结果表明:当采用非同步释放时,塔顶偏位波动明显,且当采用循环释放时,中跨侧中塔柱根部会出现拉应力;采用交替释放的加劲梁上、下缘应力最大值明显大于同步释放与循环释放方案;临时拉索索力释放过程中加劲梁压缩,主缆锚点向中跨移动,致使同步、交替、循环释放方案的吊索索力在体系转换完成后均变小,仅体系转换过程中的索力变化规律存在差异;临时拉索不同步释放会增大索鞍两侧主缆索力差,使索鞍抗滑移安全系数减小,其中交替释放的索鞍抗滑移安全系数最小为1.98,不满足规范要求;3种释放方案对吊索外侧到锚固导管口的径向偏差影响较小;对于此类通过临时锚碇实现“先缆后梁”施工的自锚式悬索桥,体系转换时应尽量采用同步释放方案,若无法实现同步,可通过增加临时拉索释放的级数,减少每级临时拉索释放时的不平衡力来实现体系转换。To study the structural stress and deformation characteristics of self-anchored suspension bridge when using temporary ground-anchor during the cable erection before girder construction,the Shatian Bridge in Dongguan was taken as the case study to establish a finite element model for the transformation from ground-anchor to self-anchor.The stress and deformation of cables,beams,and pylons were analyzed during three transition processes:temporary cables synchronous release,alternately release from both banks,and cyclic release.The variation rules of saddle anti-slip safety factors during system transformation were compared.The result indicates that when the asynchronous release is employed,the pylon top displacement fluctuates significantly.The tensile stress appears at the root of central pylon column during cyclic release.The maximum stresses at the upper and lower edges of stiffening beam by using alternately release are notably greater than those by using synchronous release and cyclic release.During the temporary cable force releasing,the stiffening beam compresses,and the main cable anchor point shifts towards the mid-span.That leads to the reduced cable forces in the synchronous,alternate,and cyclic release schemes when the transition is completed.Only the cable force variation rules during system transformation are different.The non-synchronous release of temporary cables increases the difference of main cable forces on both sides of saddle,and reduce the anti-slip safety factor.The minimum anti-slip safety factor of alternately released saddle is 1.98,which does not meet the relevant regulation requirements.The influence of three releasing schemes on the radial deviation from sling outer side to anchorage pipe orifice is little.For self-anchored suspension bridges,utilizing temporary anchorage for cable erection before girder construction,it is supposed to adopt the synchronous release scheme whenever possible.If the synchronization cannot be achieved,the system transformation can be realized by increasin

关 键 词：桥梁工程 体系转换 先缆后梁 自锚式悬索桥 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]