钢箱梁顶推上跨既有线路施工临时结构研究  

作　　者：周志慧 

机构地区：[1]中铁二十二局集团第一工程有限公司,哈尔滨150000

出　　处：《科技创新与应用》2024年第15期79-82,共4页Technology Innovation and Application

摘　　要：钢箱梁顶推施工是现阶段最常见的一种跨线、跨山河的施工方式之一,但施工前需对其进行完备的安全验算,尤其是顶推施工过程中所涉及的临时施工结构。以哈尔滨东三环快速路工程某钢箱梁顶推施工为例,对该顶推施工项目所设计的6组顶推临时支墩和2组拼装临时支架进行施工验算。结果表明,临时结构中立柱的最大应力为σ_(max)=120.1 MPa≤[σ]=190.0 MPa,腹杆的最大应力为σ_(max)=114.0 MPa≤[σ]=190.0 MPa,且均发生在顶推临时支墩上,但均能满足相关规范要求。顶推支墩和拼装支架的最大挠度分别为u_(max)=28.8 mm≤[u]=22000/300=73.3 mm、u_(max)=2.0 mm≤[u]=22000/600=36.7 mm,均能满足相关规范的要求。在顶推支墩的桩基强度验算中,其轴力和弯矩也均能满足规范要求,但在进行拼装支架的浅基础强度校核中发现,基础所受的最大应力为f=F/A=1351/(5×1.5)=180 kPa>[f]=150 kPa,所以在实际施工时需要对地基进行加固处理来满足现场施工的要求。Steel box girder jacking construction is one of the most common cross-line,cross-mountain and river construction methods at the present stage,but it needs complete safety check calculation before construction,especially the temporary construction structure involved in the jacking construction process.Taking the construction of a steel box girder in Harbin East Third Ring Expressway project as an example,the construction of 6 groups of temporary piers and 2 groups of assembled temporary supports designed in this project are checked and calculated.The results show that the maximum stress of the column in the temporary structure isσmax=120.1 MPa≤[σ]=190.0 MPa,and the maximum stress of the ventral bar isσmax=114.0 MPa≤[σ]=190.0 MPa,and both occur on the temporary buttress pier,but they can meet the requirements of the relevant specifications.The maximum deflection of the jacking piers and assembled supports is umax=28.8 mm≤[u]=22000/300=73.3 mm and umax=2.0 mm≤[u]=22000/600=36.7 mm,respectively,which can meet the requirements of relevant specifications.In the strength checking calculation of the pile foundation of the top thrust piers,the axial force and bending moment can also meet the requirements of the code.However,in the strength checking of the shallow foundation for assembling the supports,it is found that the maximum stress on the foundation is f=F/A=1351/(5×1.5)=180 kPa>[f]=150 kPa.Therefore,in the actual construction,it is necessary to strengthen the foundation to meet the requirements of site construction.

关 键 词：钢箱梁 桥梁施工 顶推 既有线路 临时结构 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]