基于有限元分析的现浇箱梁支架稳定性研究

Research on the Stability of Cast-in-situ Box Girder Support Based on Finite Element Analysis

现浇支架因通用性好、易于拆卸、结构承载力较高等优点,在桥梁基础构造中得到广泛应用,但近年来发生的现浇支架倒塌事件也为其稳定性问题带来挑战。文章以某现浇桥梁工程为背景,基于有限元分析软件,计算分析了该现浇支架的强度、刚度和稳定性。结果表明:支架搭设过程中,应合理添加纵横剪刀撑,立柱底托宜支垫木板,以协调贝雷梁变形,减少支架弯曲作用;贝雷梁在临时墩顶存在较大应力,施工贝雷梁应添加并固定支撑架;柱顶横垫梁在柱顶支撑处局部应力过大,应加强焊接加劲肋,局部可采用两排双拼I45b工字钢加强,以改善局部受力状态。

Due to the advantages of good versatility,easy disassembly,and high structural bearing capacity and so on,the cast-in-place support is widely used in the bridge foundation construction.However,the collapse events of cast-in-place supports in recent years have also brought challenges to their stability.Taking the cast-in-place bridge project as the background,based on the finite element analysis software,the strength,stiffness,and stability of the cast-in-place support are calculated and analyzed.The results show that:during the process of support erection,longitudinal and horizontal diagonal bridgings should be reasonably added,and wooden boards should be supported at the bottom of the column to coordinate the deformation of the Bailey beam and reduce the bending effect of the support;there is significant stress on the temporary pier top of the Bailey beam,and the support frame should be added and fixed during the construction of the Bailey beam;the horizontal pad beam at the top of the column has excessive local stress at the top support,and reinforcement ribs should be welded.Two rows of double spliced I45b I-beams can be used locally to improve the local stress state.