顶推施工桥梁顶升模拟试验分析研究

Simulation Test Study on Jacking Construction of Bridge Jacking

本文以三跨预应力混凝土连续槽型梁顶推施工为工程背景,在顶推前对槽型梁进行顶升模拟试验,用以检验顶推过程中导梁与混凝土连接处、槽型梁关键截面的受力是否安全。首先通过Midas/Civil有限元软件建立桥梁模型,对顶推进行全过程施工仿真计算,确定桥梁顶推过程中最不利工况,在此基础上通过顶升加载模拟最不利工况下的梁体受力,通过试验过程中的变形、应力监测,将实测值与理论计算值对比分析,结果表明前导梁、槽型梁具有足够的刚度、强度安全储备,且结构基本处于弹性工作状态,整个顶升试验的顺利实施可为类似顶推桥梁施工提供实践参考。

This article is set against the backdrop of the construction of prestressed concrete continuous box girder by incremental launching in a three-span structure.Prior to the launching process,a lifting simulation test is conducted on the box girder to verify the structural integrity and safety of the connection between the guiding beams and concrete,as well as the critical sections of the box girder during the launching process.Firstly,the bridge model is established by Midas/Civil finite element software,and the whole process construction simulation calculation is carried out to determine the most unfavorable working conditions in the launching process of the bridge.On this basis,the force of the beam under the most unfavorable working conditions is simulated by launching loading.Through the deformation and stress monitoring in the test process,the measured value is compared with the theoretical calculation value.The results show that the front guide beam and trough beam have sufficient stiffness and strength safety reserve,and the structure is basically in elastic working state.The smooth implementation of the whole test can provide practical reference for similarincremental launching bridge construction.