非对称大吨位预制箱梁分幅架设试验研究

发布时间：2018-10-16 16:41

【摘要】：近年来,预制装配化技术以其施工速度快、安全、环保及对周围交通环境影响小等优点在桥梁建设中得到了越来越广泛的应用。作为桥梁上部结构,大吨位整孔预制混凝土箱梁也顺应着时代在逐渐发展。大吨位整孔预制箱梁架设技术的发展对我国城市化建设及桥梁建设水平的提高有积极的影响。当在既有道路上修建高架桥时,由于受已有道路宽度要求的限制,非对称大吨位预制混凝土箱梁的使用,必将成为桥梁建设发展的必然趋势。目前主要对对称大吨位预制箱梁架设过程中箱梁及下部结构受力情况进行了研究,对非对称大吨位预制箱梁分幅架设过程中箱梁及下部结构受力情况研究相对较少。某高速公路工程桥梁上部结构为非对称大吨位混凝土箱梁,采用工厂化集中预制、梁上运梁、分幅架设的技术方案,在我国陆地常规公路桥梁中首次采用。为更加深入的了解非对称大吨位预制箱梁分幅架设过程中箱梁及下部结构的受力情况,本文依托工程背景,采用有限元数值分析和现场试验测试的方法,对箱梁及下部结构的受力情况进行研究。主要有以下研究内容:(1)对非对称大吨位预制箱梁分幅架设施工工艺进行介绍,明确箱梁分幅架设过程中各荷载工况。运用Midas/Civil建立非对称大吨位预制箱梁梁单元有限元模型,并采用架梁过程中各荷载工况对箱梁进行加载得到相应分析结果。研究表明,运梁车运梁到位工况为箱梁最不利工况;(2)运用ANSYS对箱梁进行最不利工况和横移到位工况下实体单元模型分析,以研究箱梁局部受力情况。研究表明,箱梁在最不利工况下纵向拉应力变化最大值出现在跨中短翼缘侧底腹板,压应力变化最大值出现在跨中短翼缘侧顶腹板;箱梁横向拉应力变化最大值出现在横移到位工况下架桥机中支腿之间;(3)对非对称大吨位预制箱梁分幅架设过程中箱梁及下部结构在各工况下的受力状态进行现场试验测试分析,比较箱梁和下部结构在各工况下的受力差异,并与理论结果进行比较。通过研究发现,运梁车运梁到位工况为箱梁最不利工况,横移到位工况为下部结构最不利工况,实测结果与理论计算结果吻合较好。
[Abstract]:In recent years, prefabricated assembly technology has been more and more widely used in bridge construction because of its advantages such as fast construction speed, safety, environmental protection and small impact on the surrounding traffic environment. As the superstructure of the bridge, the large-tonnage prefabricated concrete box girder conforms to the development of the times. The development of large-tonnage prefabricated box girder erection technology has a positive impact on the urbanization construction and the improvement of bridge construction level in China. When the viaduct is built on the existing road, the use of asymmetric large-tonnage precast concrete box girder is bound to become the inevitable trend of the bridge construction development due to the restriction of the width of the existing road. At present, the stress situation of box girder and its substructure during the erection of symmetrical large-tonnage prefabricated box girder is mainly studied, and the research on the stress situation of box girder and its substructure in the course of asymmetric large-tonnage precast box girder erection is relatively few. The superstructure of a highway bridge is an asymmetric large-tonnage concrete box girder, which is first adopted in the conventional highway bridges on land in our country. In order to understand the stress of the box girder and its substructure during the erection of asymmetric large-tonnage prefabricated box girder, the finite element numerical analysis and field test method are adopted in this paper, based on the engineering background. The stress of box girder and substructure is studied. The main research contents are as follows: (1) the construction technology of asymmetric large-tonnage prefabricated box girder is introduced. The finite element model of asymmetric large-tonnage prefabricated box girder element is established by using Midas/Civil, and the corresponding analysis results are obtained by loading the box girder under various load conditions during the beam erection process. The results show that the most unfavorable condition of the box girder is the working condition of carrying beam in place. (2) using ANSYS to analyze the entity element model of the box girder under the most unfavorable working condition and the transversely moving condition to study the local force situation of the box girder. The results show that the maximum of longitudinal tensile stress of box girder under the most unfavorable working condition appears in the side web of span short flange and the maximum of compressive stress appears in the top web of side top of span short flange. The maximum change of transverse tensile stress of box girder appears between the supporting legs of the bridge erector under the condition of transverse displacement. (3) the field test and analysis of the stress state of the box girder and its substructure under various working conditions during the erection of asymmetric large-tonnage prefabricated box girder are carried out. The stress differences between box girder and substructure under different working conditions are compared and compared with the theoretical results. Through the research, it is found that the box girder is the most unfavorable working condition and the transversal position is the most unfavorable working condition. The measured results are in good agreement with the theoretical calculation results.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.4;U446

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