铰接空心板桥整体受力性能研究

发布时间：2018-03-06 21:30

本文选题：铰接空心板桥　切入点：铰缝　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：铰接空心板桥是我国中小跨径桥梁中的一种主要桥型。在实际应用中,铰缝病害是上部结构最为常见的病害形式,会导致横向连接逐步失效,最终使得“单板受力”现象出现,对这类桥梁的使用寿命和交通安全造成巨大的威胁。为了更清楚地了解铰接空心板桥的整体受力性能,为新建铰接空心板桥铰缝构造的改进提供依据,本文以铰接空心板桥为对象,开展试验研究和有限元分析。主要工作和得到的主要结论为：(1)对铰接空心板桥的发展历程进行总结,通过对比根据1989年颁布规范制定的旧标准图和2004年颁布规范制定的新标准图中空心板构造和铰缝构造的异同点,统计分析了铰接空心板桥的空心板和铰缝构造参数,为本文研究提供参考和依据。(2)按照新标准图的8m铰接空心板桥,制作了足尺试验模型,并进行了车辆荷载作用下整体受力性能试验。当试验荷载约70kN时,铰缝构造跨中截面底部砂浆层出现裂缝,铰缝构造开裂导致铰缝传力性能下降,使各空心板挠度呈不均匀分布；当试验荷载约80kN时,3片空心板跨中截面底部出现横向裂缝：当试验荷载达到300kN时,空心板1/4截面至3/4截面底部和腹板内分布着大量横缝,铰缝底部砂浆层分布纵桥向裂缝。(3)应用ABAQUS程序建立铰接空心板整体受力性能试验有限元模型,计算得到的空心板荷载-挠度曲线、荷载-铰缝横向张开量曲线、空心板底荷载-纵向应变、空心板主筋荷载-纵向应变、结合面构造钢筋荷载-应变曲线和裂缝分布结果与试验结果吻合良好,可采用该非线性有限元模型进行铰接空心板整体受力性能分析。在空心板与铰缝结合面有法向、竖向和纵向三个方向,应当以竖向滑移量作为结合面粘结破坏失效的指标。由于空心板与饺缝结合面的开裂先于空心板和铰缝构造,使其成为铰接空心板桥最薄弱的部位。(4)讨论结合面门式构造钢筋、混凝土强度和结合面粘结滑移刚度三个参数对铰接空心板桥整体受力性能的影响。结果表明,对于新标准图中增设的空心板与铰缝结合面之间的门式构造钢筋,不能明显地提高结合面的开裂荷载,但可以延缓空心板与铰缝结合面竖向通缝和纵桥向通缝的形成；增大空心板与铰缝结合面构造钢筋直径对结合面开裂荷载和形成通缝荷载和最终的裂缝分布没有明显改善；增大混凝土强度对空心板与铰缝结合面的改善作用有限；粘结滑移刚度的提高,对空心板与铰缝结合面开裂荷载无明显提高,但使结合面形成竖向通缝荷载得到提高,对竖向通缝和底部裂缝沿纵桥向分布得到一定地限制。
[Abstract]:Hinged hollow slab bridge is one of the main bridge types in middle and small span bridges in our country. In practical application, hinge joint disease is the most common disease form of superstructure, which will lead to the gradual failure of transverse connection and eventually make the phenomenon of "single plate bearing force" appear. It poses a great threat to the service life and traffic safety of this kind of bridge. In order to better understand the overall mechanical performance of the hinged hollow slab bridge, it provides the basis for the improvement of the hinge joint structure of the new hinged hollow slab bridge. In this paper, experimental research and finite element analysis are carried out on hinged hollow slab bridge. The main work and main conclusion is: 1) summarize the development course of hinged hollow slab bridge. By comparing the differences and similarities between the hollow slab structure and the hinged joint structure in the old standard chart drawn up according to the standards promulgated on 1989 and the new standard chart issued on 2004, the structural parameters of hollow slab and hinge joint of hinged hollow slab bridge are statistically analyzed. According to the new standard diagram of 8m articulated hollow slab bridge, the full-scale test model is made, and the overall mechanical behavior test under vehicle load is carried out. When the test load is about 70kN, Cracks appear in the mortar layer at the bottom of the cross-section of the hinged joints, which leads to the decrease of the force transfer performance of the hinged joints and the uneven distribution of the deflection of the hollow plates. When the test load is about 80kN, three hollow slabs appear transverse cracks at the bottom of the mid-span section. When the test load reaches 300kN, a large number of transverse joints are distributed between the bottom of section 1/4 and the bottom of section 3/4 and the web plate. ABAQUS program is used to establish the finite element model of integral mechanical performance test of hinged hollow slabs. The load-deflection curve and load-hinge joint transverse opening curve are calculated. The load-longitudinal strain at the bottom of the hollow slab, the load-longitudinal strain on the main reinforcement of the hollow slab, the load-strain curve and the crack distribution of the reinforced bar in the combined plane are in good agreement with the experimental results. The nonlinear finite element model can be used to analyze the overall mechanical behavior of hinged hollow slabs. The vertical slip should be taken as the index of bond failure failure of the joint surface. Because the crack of the joint surface of hollow slab and dumpling joint precedes the structure of hollow slab and hinge joint, it becomes the weakest part of hinged hollow slab bridge. The effect of three parameters of concrete strength and bond-slip stiffness on the overall mechanical behavior of hinged hollow slab bridge is discussed. The results show that the gate reinforcement between the hollow slab and the hinge joint is added in the new standard diagram. The cracking load of the joint surface can not be increased obviously, but it can delay the formation of the vertical through joint and the longitudinal bridge joint of the joint plane between the hollow slab and the hinged joint. Increasing the diameter of steel bar on the joint surface of hollow slab and hinge joint has no obvious improvement on the cracking load and the forming load of joint and the final crack distribution, but increasing the strength of concrete has limited effect on the improvement of the joint surface between hollow slab and hinge joint. With the increase of bond-slip stiffness, the cracking load on the joint surface of hollow slab and hinge joint is not obviously increased, but the load of vertical joint formed on the joint surface is increased, and the distribution of vertical joint and bottom crack along the longitudinal bridge is restricted to a certain extent.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441

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