上跨桥钢混组合梁顶推施工关键技术研究

Study on Key Technologies in Incremental Launching Construction of Overpass Steel-Concrete Composite Beams

摘要:

以某上跨桥钢混组合梁顶推施工为例，提出了钢混组合梁顶推施工及临时支架设计方案，借助数值模拟手段开展了顶推施工过程的受力分析。结果表明，顶推施工中支架最大综合应力位于支架主立柱顶端分配梁位置，为59.92 MPa，低于设计允许值205 MPa，为设计允许值的29.2%，最大变形量位于分配梁中心位置处，为1.92 mm。顶推施工中叠合梁和导梁最大组合应力分别为77 MPa和74MPa，分别为各自容许应力的28%和39%。叠合梁最大前悬下挠、后悬下挠和跨中挠度分别为60、38、22 mm，导梁最大位移为163 mm，在设计规范预警值范围内。叠合梁最大前悬和后悬抗倾覆比分别为2.48和2.99，均大于规范要求的1.3，分别为规范允许值的190%和230%，表明叠合梁能满足抗倾覆稳定性的要求。研究成果可为钢混组合梁支架设计和顶推施工提供参考。

Abstract:

Taking the incremental launching construction of steel-concrete composite beams of overpass as an example, an incremental launching construction scheme of the steel-concrete composite beam and a design scheme of temporary support are proposed. The force analysis of the incremental launching construction process is carried out by means of numerical simulation. The results indicate that the maximum comprehensive stress in the support during the incremental launching construction is located at the top distribution beam position of the main column of the support, which is 59.92 MPa, and is below the design allowable value of 205 MPa, representing 29.2% of the design allowable value. The maximum deformation is located at the center of the distribution beam, which is 1.92 mm. During the incremental launching process, the maximum combined stresses in the composite beam and the guide beam are 77 MPa and 74 MPa respectively, accounting for 28% and 39% of their respective allowable stresses. The maximum deflections of the composite beam at the front cantilever, rear cantilever and mid-span are 60 mm, 38 mm and 22 mm respectively, and the maximum displacement of the guide beam is 163 mm, all within the warning values of the design specifications. The anti-overturning ratios of the composite beam at the front and rear cantilevers are 2.48 and 2.99 respectively, both exceeding the code requirement of 1.3, representing 190% and 230% of the allowable values respectively, which indicates that the composite beam can meet the requirements of anti-overturning stability. The research findings can provide a reference for the design of supports and the incremental launching construction of steel-concrete composite beams.