带协作跨预应力混凝土斜拉桥裂缝成因分析及防治对策

发布时间：2018-01-17 21:15

本文关键词：带协作跨预应力混凝土斜拉桥裂缝成因分析及防治对策　出处：《长安大学》2016年硕士论文　论文类型：学位论文

【摘要】：带协作跨的预应力混凝土斜拉桥由于其良好的经济性、稳定性以及施工便利性在工程中得到广泛的应用,而在施工、运营过程中的开裂问题一直是困扰工程界的重要问题。文章以某带协作跨的预应力混凝土斜拉桥为工程背景,采用有限元分析软件Midas Civil和Midas FEA建立全桥的整体有限元模型和局部有限元模型,对其裂缝成因进行了仿真分析,主要完成了以下工作:(1)通过试验检测,对该桥在检测过程中发现的裂缝进行统计,发现两侧协作跨以及主跨无索区开裂较为严重,主要表现为腹板开裂以及少数底板裂缝。腹板斜裂缝较多,尤其在21#墩两侧的分布较为规律,主跨无索区和西侧协作跨的腹板裂缝在墩截面两侧基本呈现对称分布规律。(2)采用有限元分析软件Midas Civil建立全桥模型,模拟其施工阶段,对其成桥受力状态和运营阶段的受力状态进行了分析,研究表明:协作跨以及主跨无索区的压应力要小于有索区的压应力,在其他不利因素的作用下,容易导致协作跨和主跨无索区产生裂缝。(3)利用整体有限元模型详细分析由于温度、基础沉降、收缩徐变、车辆荷载等因素对裂缝成因的贡献作用,得出其主要影响因素。研究结果表明:两侧协作跨的超载和温度作用是导致该协作体系斜拉桥产生裂缝的主要因素。(4)采用有限元分析软件Midas FEA建立局部有限元模型,考虑了混凝土和钢筋的材料非线性,对荷载作用下主梁的受力状态进行分析,研究结果表明:在温度和超载作用下,主梁的腹板在桥墩截面两侧出现了较大的主拉应力,开裂位置与实际检测结果基本吻合。本文的研究对于协作体系混凝土斜拉桥的裂缝成因及裂缝控制具有重要的参考意义。
[Abstract]:Prestressed concrete cable-stayed bridge with cooperative span is widely used in construction because of its good economy, stability and construction convenience. The cracking problem in operation is always an important problem in the engineering field. This paper takes a prestressed concrete cable-stayed bridge with cooperative span as the engineering background. The integral finite element model and local finite element model of the whole bridge are established by using the finite element analysis software Midas Civil and Midas FEA, and the causes of the cracks are simulated and analyzed. Mainly completed the following work: 1) through the test of the bridge in the process of detection of cracks found in statistics, found that the two sides of the cooperative span and the main span without cable cracking is more serious. The main manifestations are web cracking and a few cracks in the bottom plate. There are more inclined cracks in the web, especially on the two sides of the 21# pier. The web crack of the main span without cable and the west side cooperative span basically presents the symmetrical distribution law on both sides of the pier section.) the finite element analysis software Midas Civil is used to establish the full bridge model. The stress state of the bridge and the operation stage are analyzed. The results show that the compressive stress of the cooperative span and the main span is smaller than that of the cable zone. Under the action of other unfavorable factors, it is easy to cause cracks in the non-cable zone of cooperative span and main span.) the integral finite element model is used to analyze in detail the shrinkage and creep due to temperature, foundation settlement and creep. The contribution of vehicle load and other factors to the cause of cracks. The main influencing factors are obtained. The results show that the overloading and temperature action of the bilateral cooperative span are the main factors leading to the cracks of the cable-stayed bridge. The local finite element model is established by using the finite element analysis software Midas FEA. Considering the material nonlinearity of concrete and steel bar, the stress state of the main beam under load is analyzed. The results show that: under the action of temperature and overload. The web plate of the main beam has a large main tensile stress on both sides of the section of the pier. The crack location is basically consistent with the actual detection results. The research in this paper has important reference significance for the crack formation and crack control of the concrete cable-stayed bridge with cooperative system.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U445.57;U448.27

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