预制空心板梁桥横向接缝设计方法研究

发布时间：2018-03-01 21:44

本文关键词： 预制空心板梁桥横向接缝应力状态开裂分析接缝设计　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：预制空心板梁桥因其结构形式简单、便于运输与安装、施工周期短等优点,在我国中小跨径桥梁建设中被广泛推广使用。然而,在运营期内对其进行检测发现,该类桥梁存在不同程度的病害问题,其中以横向接缝的损伤最为严重。横向接缝作为将各空心板梁连接成整体共同工作的关键构件,其承担着荷载横向传递的重要任务,一旦失效则会降低结构的整体性,严重时将引发“单板受力”的病害,危及结构的安全。为此,诸多学者对空心板梁桥横向接缝病害问题进行了研究,对引发接缝病害的原因进行了总结,并提出了相应的改进措施与加固方法,但仍没能有效地彻底解决横向接缝损伤的问题。因此,本文以预制空心板梁桥横向接缝为研究对象,应用有限元软件ANSYS对接缝内实际的内力状态进行分析,探究改进接缝性能的方法,为此本文进行的分析如下:首先针对目前预制空心板梁桥的设计理论与方法进行了归纳与分析,总结了设计中因简化计算而引入的理论假设,并探究了设计方法中引发误差的原因,根据横向接缝的受力特点提出了相应的改进形式。应用有限元软件ANSYS对预制空心板梁桥结构进行了有限元模拟分析,通过模拟实际的车辆荷载,获得了结构在不同的荷载工况下横向接缝内实际的应力状态。分析结果显示,横向接缝并不符合铰接板法中“铰”的假设,其更符合半刚性连接的特性,既传递竖向剪应力,又传递横向弯矩。本文分析了接缝改进前后其内部各向应力的分布规律,结果显示接缝内混凝土受多向应力共同作用,且较大的纵向正应力与横向正应力的存在已经对接缝的安全性产生了影响。通过有限元模拟探究了接缝内构造钢筋对接缝受力性能的影响,同时对结构进行了开裂分析,通过对比接缝内不同钢筋布置下结构裂缝的分布情况,从而得出接缝内构造钢筋在接缝防裂中的作用,根据分析结果给出了横向接缝内构造钢筋合理的布置形式。对预制空心板梁桥设计提出一定的改进建议,通过对改进前后结构进行有限元模拟,对比二者接缝中的应力状态,对改进设计的有效性进行评定。同时,建议对结构增设横向预应力,该方法可以有效降低接缝内部横向正应力值,改善接缝内的应力状态,从而使结构的整体性与安全性得到保证。
[Abstract]:The prefabricated hollow slab girder bridge is widely used in the construction of medium and small span bridges in China because of its simple structure, convenient transportation and installation, short construction period and so on. The damage of transverse joint is the most serious in this kind of bridge. As the key member of connecting the hollow slab beam to work together, the transverse joint takes on the important task of transversal load transfer. Once failure will reduce the integrity of the structure, it will lead to the "single plate force" disease, which endangers the safety of the structure. Therefore, many scholars have studied the problem of transverse joint disease of hollow slab girder bridge. In this paper, the causes of joint diseases are summarized, and the corresponding improvement measures and reinforcement methods are put forward, but the problem of transverse joint damage is still not solved effectively. Therefore, this paper takes the transverse joint of prefabricated hollow slab girder bridge as the research object. The actual internal force state in the butt joint is analyzed by using the finite element software ANSYS, and the method of improving the joint performance is explored. The analysis of this paper is as follows: firstly, the design theory and method of prefabricated hollow slab girder bridge are summarized and analyzed, and the theoretical assumptions introduced in the design for simplified calculation are summarized. The causes of the errors in the design method are explored, and the corresponding improvement forms are put forward according to the stress characteristics of the transverse joints. The finite element simulation analysis of the precast hollow slab girder bridge structure is carried out by using the finite element software ANSYS. By simulating the actual vehicle load, the actual stress state in the transverse joint of the structure under different load conditions is obtained. The analysis results show that the transverse joint does not accord with the hypothesis of "hinge" in the hinge plate method. It is more in line with the characteristics of semi-rigid connection, which transfers both vertical shear stress and transverse moment. In this paper, the distribution of internal stresses in joints before and after improvement is analyzed. The results show that concrete in joints is subjected to multi-direction stress. The existence of larger longitudinal normal stress and transverse normal stress has had an impact on the safety of the butt joint. Through finite element simulation, the influence of the mechanical behavior of the butt joint of the steel bar in the joint structure has been explored, and the cracking analysis of the structure has been carried out at the same time. By comparing the distribution of structural cracks under different reinforcement arrangement in joints, the function of structural reinforcement in crack prevention is obtained. According to the results of the analysis, the reasonable arrangement of the steel bars in the transverse joint is given. Some suggestions for improving the design of the precast hollow slab girder bridge are put forward, and the stress states in the joints are compared by the finite element simulation of the structure before and after the improvement. The effectiveness of the improved design is evaluated. At the same time, it is suggested that the transverse prestress should be added to the structure. This method can effectively reduce the transverse normal stress in the joint and improve the stress state in the joint. Thus, the integrity and safety of the structure are guaranteed.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.5

【参考文献】