先简支后连续预应力混凝土小箱梁提运梁工况分析验算

Analysis and Checking Computation of Simple Supported-Continuous Prestressed Concrete Small Box Girder Bridge under the Lifting and Transporting Beam Conditions

针对目前利用门式起重机提运梁施工工艺,结合工程背景资料,基于极限状态分析方法,依据梁格法计算理论,对宽跨比较大的先简支后桥面连续的预应力混凝土小箱梁桥提梁运梁工况进行分析验算。纵向采用梁格法建立三维有限元分析模型,依据《公路钢筋混凝土及预应力混凝土桥涵设计规范》对其进行分析验算;横向无预应力钢束,故按钢筋混凝土结构依据现行规范进行裂缝宽度验算。标准值组合作用下,主梁下缘最大压应力为17.9 MPa;提梁工况作用下,底板最大裂缝宽度为0.18 mm,均满足规范要求。

Aiming at the current construction technology of lifting and transporting beams by gantry crane,based on the limit state analysis method,combining the engineering background data,according to the calculation theory of grillage method,the working conditions of lifting and transporting beams of prestressed concrete small box girder bridge with large width span ratio are analyzed and checked.The finite element software is used to check the vertical and horizontal directions of the prestressed concrete small box girder bridge.Longitudinal grid method is used to establish a three-dimensional analysis model,which is analyzed and checked according to the"Specifications for Design of Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts";There is no transverse prestressing tendon,so the crack width is checked according to the existing specifications for reinforced concrete structures.Under the action of standard value combination,the maximum compressive stress at the lower edge of the main beam is 17.9 MPa;Under the working condition of lifting beam,the maximum crack width of bottom plate is 0.18 mm,which meets the standard requirements.