步履式顶推施工工艺对钢箱梁局部受力的分析研究

发布时间：2018-08-25 10:01

【摘要】：本文首先简要地介绍了顶推施工法的应用与发展历史,对比了传统拖拉式顶推与新型步履式顶推两者的优缺点。随后,以昆明南连接线铁路跨线桥为工程背景详细描述了新型步履式顶推施工工艺的控制系统与施工工序,并在此基础上,采用Midas Civil有限元软件建立了全桥杆系有限元模型,进行了顶推施工全过程的仿真分析,了解顶推过程梁体的整体受力,确定了顶推过程中混凝土桥面板与钢箱梁的最不利工况；在最不利工况下,运用ANSYS大型有限元分析软件,建立全桥梁-壳-实-接触混合有限元模型,着重分析了钢箱梁与橡胶垫块的接触状态,以此来说明在支承区域范围内主梁各构件的局部受力情况。最后,结合工程实际,进行了相关参数对钢箱梁局部受力的分析研究,总结出一些规律,为今后更多采用步履式顶推施工法的桥梁提供参考与借鉴。分析研究成果如下：1)在钢混组合梁桥中,混凝土桥面板通过剪力连接件与钢箱梁形成整体,共同受力,因此在该处的混凝土桥面板受力较大,在某些工况下顶面存在开裂风险；2)橡胶垫块能较好地适应支承区域内梁体的转角位移,从而使梁体受力均匀,而钢垫块则使得支承区域内梁体局部受力效应明显,构件应力水平较大。3)刚度较小的橡胶垫块通过改善梁底与其接触的不均匀性来影响构件的局部受力,而垫块宽度则通过横向转移支承区域内支反力的作用点来影响构件的局部受力；4)分析了顶推液压不同步对构件局部受力的影响。得出同一墩上左右两侧纵向顶推不同步比竖向顶升不同步对构件局部受力的影响大,且顶推不同步均会造成梁体中轴线的横向偏移,最后确定了该桥顶推不同步下的安全控制阈值；
[Abstract]:This paper introduces briefly the application and development history of the push-push construction method, and compares the advantages and disadvantages between the traditional tow-push method and the new-type walking push-push method. Then, the control system and construction procedure of the new walking pushing construction technology are described in detail with the engineering background of Kunming South Link Railway Bridge. On the basis of this, the finite element model of the whole bridge bar system is established by using Midas Civil finite element software. The simulation analysis of the whole process of jacking construction is carried out to understand the whole force of the beam body during the jacking process, and the most unfavorable working conditions of concrete bridge deck and steel box girder are determined. Under the most unfavorable working conditions, the ANSYS software is used to analyze the whole body of the beam. The hybrid finite element model of the whole bridge, shell and real contact is established, and the contact state between the steel box girder and the rubber cushion is analyzed emphatically, so as to explain the local force of the main beam members in the support area. Finally, combined with the engineering practice, the analysis and research on the local force of steel box girder are carried out, and some rules are summarized, which can provide reference for more bridges which adopt the step pushing construction method in the future. The research results are as follows: (1) in the steel-concrete composite beam bridge, the concrete deck slab forms a whole force with the steel box girder through the shear connection, so the concrete deck slab in the place has a large force. Under some working conditions, there is a risk of cracking on the top surface. 2) the rubber gasket can better adapt to the angular displacement of the beam body in the supporting area, so that the beam body is subjected to uniform force, while the steel cushion block makes the local force effect of the beam body in the supporting area obvious. The rubber cushion with lower stiffness and greater stress level affects the local force of the member by improving the non-uniformity of the contact between the beam bottom and the member. The width of the gasket affects the local force of the member by transference the acting point of the support reaction force in the support area. 4) the influence of the non-synchronism of the thrust hydraulic pressure on the local force of the member is analyzed. It is concluded that the longitudinal push on the left and right sides of the same pier has more influence on the local force of the member than that on the vertical uplift, and the lateral deviation of the central axis of the beam will be caused by the non-synchronous push. Finally, the safety control threshold of the bridge is determined.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.462

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