简支转连续T形梁桥预应力筋的应力增量分析

发布时间：2018-03-04 21:31

本文选题：简支转连续　切入点：预应力钢筋　出处：《东北林业大学》2015年硕士论文　论文类型：学位论文

【摘要】：在我国桥梁建设过程中,预应力混凝土简支转连续T梁桥以其受力与施工方面的诸多优点被大量的采用。该种桥型采用预应力技术,对提高桥梁的跨越能力以及使用性能起到很大作用。预应力技术采用高强材料,可有效的减小构件中钢材与混凝土的工程用量,降低工程造价,同时可改善混凝土构件的使用性能。预应力结构中预应力钢筋是其关键的受力构件,预应力筋的应力分布及其变化直接影响桥梁结构承载力、刚度的变化。因此,鉴于其重要性,对该种桥型主梁预应力筋应力变化进行研究。本文以三跨预应力混凝土简支转连续T梁桥—宝贝河大桥为依托,对试验梁各施工阶段预应力钢筋应力值进行测试。使用Midas/Civil有限元软件建立试验桥有限元模型,计算各施工阶段测点位置预应力钢筋的理论应力值,通过对实测数据与理论计算数据对比分析,验证有限元模型的正确性。根据试验桥梁有限元模型的计算结果,对各个施工阶段预应力钢筋的应力分布进行分析,并对应力增量进行讨论,得出不同的施工阶段对预应力钢筋应力增量的影响。桥梁使用阶段,在不同车道布载情况下,对纵桥向各截面预应力钢筋应力增量进行讨论,还对同跨各T梁不同截面预应力筋应力增量进行分析,得出偏载时,偏载侧边梁预应力筋应力增量最大,中载时3#梁预应力筋应力增量最大。
[Abstract]:In the process of bridge construction in China, prestressed concrete simply supported continuous T-beam bridge is widely used for its advantages in force and construction. It plays a great role in improving the span capacity and performance of bridges. The use of high-strength materials in prestressing technology can effectively reduce the engineering consumption of steel and concrete in the members and reduce the project cost. At the same time, the performance of concrete members can be improved. In prestressed structure, prestressed steel bar is the key member. The stress distribution and its change of prestressed tendons directly influence the change of bearing capacity and stiffness of bridge structure. In view of its importance, the stress change of prestressed tendons of this kind of main girder is studied. The stress value of prestressed steel bar in each construction stage of test beam is tested. The finite element model of test bridge is established by using Midas/Civil finite element software, and the theoretical stress value of prestressed steel bar at each construction stage is calculated. The validity of the finite element model is verified by comparing the measured data with the theoretical calculation data. According to the calculation results of the finite element model of the test bridge, the stress distribution of the prestressed steel bar in each construction stage is analyzed. The influence of different construction stages on the stress increment of prestressed steel bar is obtained. In the use of bridge, the stress increment of prestressed steel bar in different sections of longitudinal bridge is discussed in the case of different driveway distribution. The stress increment of prestressed tendons in different sections of T-beams with the same span is also analyzed. The results show that the stress increment of prestressed tendons is the largest in the lateral beams under eccentric loads and the largest in the beams at mid-load.
【学位授予单位】：东北林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.212

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