跨航道预应力连续梁桥拆除施工方案研究  

Research on Demolition Scheme of Prestressed Continuous Girder Bridge over the Channel

作　　者：潘小虎 陈国 狄小东[1] 吴新涛 窦晗 PAN Xiaohu;CHEN Guo;DI Xiaodong;WU Xintao;DOU Han(China Railway First Group Third Engineering Co.Ltd.,Baoji Shaanxi 721006,China;College of Civil Engineering,Nanjing Forestry University,Nanjing Jiangsu 210037,China)

机构地区：[1]中铁一局集团有限公司第三工程分公司,陕西宝鸡721006 [2]南京林业大学土木工程学院,江苏南京210037

出　　处：《铁道建筑技术》2023年第8期132-135,共4页Railway Construction Technology

基　　金：国家自然科学基金项目(52178220)。

摘　　要：为研究跨航道大跨连续箱梁桥拆除施工对大跨径变截面预应力混凝土箱梁受力性能和变形特性的影响,以京沪高速公路原盐河大桥为工程背景,采用有限元软件建立旧桥三维数值模型,根据跨航道桥特点,针对性提出3种拆除方案,即先边跨后中跨方案(方案Ⅰ)、边跨和中跨同步拆除方案(方案Ⅱ)以及先中跨后边跨拆除方案(方案Ⅲ),并对各方案施工安全性和施工难易程度进行对比分析。结果表明,先中跨后边跨拆除方案(方案Ⅲ)对航道通过能力影响最小,可显著降低施工过程安全风险;最不利受力阶段出现在桥面二期铺装和翼缘板拆除后,中跨箱梁顶(底)板应力及竖向变形为全施工过程最大值。In order to study the effect of the demolition construction of long-span continuous box girder bridge over the channel on the mechanical and deformation performance of long-span variable cross-section prestressed concrete box girders,taking the former Yanhe Bridge in Beijing-Shanghai High-speed Highway as engineering example,the three-dimensional numerical model of old bridge was built using finite element software.Based on the characteristic of the continuous beam bridge crossing the channel,three demolition schemes were proposed,including side span first and midspan later scheme(methodⅠ),side span and midspan simultaneous scheme(methodⅡ),and midspan first and side span later scheme(methodⅢ).The effects of each demolition scheme on the safety and construction difficulty of the box girder bridge were compared and analyzed.It is found that the methodⅢhas minimal impact on the waterway transit capacity,and the security risk can be reduced significantly during the process of demolition.The most dangerous stress state of the box girder bridge appears when the deck pavement and flanges are removed,and the normal stress of the top(bottom)plate and vertical deformation of the midspan box girder reaches their maximum.

关 键 词：公路桥梁 连续梁桥 改扩建 跨航道 拆除方案 数值模拟 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] U445.6[交通运输工程—道路与铁道工程]