2014年12月上第43卷
D01;10.7672/sgjs2014230079
施工技术
CONSTRUCTIONTECHNOLOGY
跨铁路混凝土箱梁顶推施工过程分析及监测
田春艳
（北京市市政工程研究院，北京
100037）
【摘要】结合上跨京广铁路立交桥施工过程，介绍了桥梁顶推施工的计算分析方法。根据结构特点与顶推方案，建立有限元模型，模拟桥梁顶推施工的全过程，详细分析了结构内力、支点反力、截面应力以及导架变形的变化规律根据顶推施工过程的分析结果制订了监测方案，并对顶力、项进速度、中线偏位、桥墩位移、箱梁应力、导渠变形等项目进行了全过程监测。当监测数据发现异常时发出预警信息并及时采取处理措施，保证了顶推施工顺利进行。【关键词】桥架工程；立交桥：项推法：监测
[中图分类号]U445.4
【文献标识码】A
【文章编号】1002-8498(2014)23-0079-05
ConstructionProcessAnalysisandMonitoringofConcreteBoxGirder oftheOverpassCrossingRailwaybyIncrementalLaunchingMethod
Tian Chunyan
(Bejing Municipal Engineering Research Institute,Bejing 100037, China)
Abstract:Based on the construction process of an overpass crossing Beijing-Guangzhou railway, the calculation and analysis methods of incremental launching construction for overpass are introduced. On the basis of structural characteristics and incremental launching scheme of the overpass, a finite element model is established to simulate incremental launching process of the whole overpass, and variation of force and deformation is analyzed in detail, including the structural internal force, supporting point reaction, section stress and deformation of the guiding girder. According to the analysis results of incremental launching process, monitoring scheme is established,and the jacking force, pushing speed, midline deviation, pier displacement, box girder stress, deformation of the guiding girder and so on are all monitored in the whole process. Early warning information is given when abnormal monitoring data is
found,and measures are taken timely to ensure incremental launching construction smoothly. Key words:bridges;overpasses;incremental launching method; monitoring
工程概况
北京市京良路改建工程上跨京广铁路，立交桥跨越铁路的第3~7号墩为4跨1联预应力混暨士连续箱梁，全长115.0m，其中主路桥跨径为（26.5+ 42.0+26.5+20.0）m，采用单箱3室、斜腹板等高度箱形截面，高2.2m。
桥梁采用顶推法施工，顶推段预制长度56m，顶推施工在梁端设置前导梁，导梁长28m。在5~8号墩之间设置1,2,3号临时墩；在4号墩靠铁路侧设置临时墩（仅作为保险措施，施工过程中不受力）；顶推过程中主梁前端最大悬臂41m，尾端最大悬臂 12.5m；顶推力41000kN（见图1）。
[作者简介】田春艳，高级工程师，E-mail;3532416@qq.com
【收稿日期】2014-06-09 万方数据
二项摊方向
R
4
5.600
1076
79
宝品际
且临时墩铁
此素是舒联糖的素糖肾最
3号墩4号端
3.6号激
7共增
主路中
心线
广州
米
图1顶推示意（单位：cm）
Fig.1 Incremental launching construction(unit:em) 顶推施工工艺如下：
1)牵引反力座设置在5号永久墩上。选用2台 500t连续顶推千斤顶，顶推过程中必须保持2台千斤顶同步。顶推动力储备系数为2.4，顶进距离63.5m。