钢板-橡胶混凝土复合覆层应用于桥墩防撞的研究

发布时间：2019-04-27 09:57

【摘要】：随着经济的发展和科技的进步,梁式桥得到了越来越广泛的应用,桥墩作为桥梁的下部结构,不仅承担着结构自重和车辆荷载,还时刻承担着遭受车辆撞击的风险,因此,研究其在撞击荷载作用下的响应和防撞对策具有重要意义。本文将波形钢板橡胶混凝土、平钢板橡胶混凝土和橡胶混凝土作为桥墩防撞层,运用锤击法和摆锤试验测试不同覆层类型的模型墩的撞击力及桥墩各动力响应,进而对三种类型覆层的实际防撞效果进行了论证。另外,运用模态应变能原理,结合通用有限元软件ABAQUS/Explicit显式非线性动态分析计算三种不同类型的覆层为模型墩提供的一阶振动模态的附加阻尼比,验证了有限元软件模拟碰撞问题的可行性。基于以上研究内容,本文可得到如下结论:(1)对于波形钢板橡胶混凝土覆层模型墩、平钢板橡胶混凝土模型墩和橡胶混凝土覆层模型墩,随着摆锤高度的增加,墩顶位移衰减段周期略微变大。(2)在摆锤下落高度相同时,橡胶混凝土覆层墩墩顶位移响应最大,平钢板橡胶混凝土覆层墩次之,波形钢板橡胶混凝土覆层墩墩顶位移响应最小。(3)不同覆层类型的模型墩撞击力峰值增长规律有所不同,波形钢板橡胶混凝土覆层墩由于波纹局部变形的作用,能够有效阻止撞击力增长过快。(4)波形钢板橡胶混凝土覆层和平钢板橡胶混凝土覆层由外层钢板局部塑性变形耗能和内层橡胶混凝土吸能来共同控制墩身应变,当外层钢板变形未发展至稳定时,钢板的局部变形耗能作用占主导,而当外层钢板的局部变形发展完全时,内层橡胶混凝土的吸能作用得到突显。(5)有限元模拟得到的墩身混凝土应变最大值、墩顶位移、背撞点和墩顶加速度最大值与试验值趋势相符,数值略大。可以认为本文采用的有限元软件ABAQUS计算桥墩在撞击荷载下动力响应的方法是可行的,从保证桥墩结构安全性的角度考虑,有限元的计算结果较为保守。(6)对波形钢板橡胶混凝土覆层和平钢板橡胶混凝土覆层,钢板不仅可充当模板,更可提供较大的侧向刚度。尤其对于波形钢板橡胶混凝土覆层,竖向波纹增大了内层橡胶混凝土与外钢板的机械咬合力,且竖向波起到加劲肋条的作用,抗侧性能较优,因此,将波形钢板或平钢板与橡胶混凝土结合作为复合型的桥墩防撞保护层,可收获令人满意的施工性能和力学性能。
[Abstract]:With the development of economy and the progress of science and technology, beam bridge has been used more and more widely. As the substructure of the bridge, the pier not only bears the weight of the structure and the load of the vehicle, but also bears the risk of the impact of the vehicle at all times, therefore, the bridge pier is the substructure of the bridge. It is of great significance to study its response under impact load and anti-collision countermeasures. In this paper, Waveform steel plate rubber concrete, flat steel plate rubber concrete and rubber concrete are used as anti-collision layer of bridge pier. The impact force and dynamic response of the model piers of different cladding types are tested by hammer-impact method and pendulum test. Furthermore, the actual anti-collision effect of three types of coating is demonstrated. In addition, the modal strain energy principle and the finite element software ABAQUS/Explicit are used to calculate the additional damping ratio of the first-order vibration modes provided by three different types of layers for the model pier, and the finite element software ABAQUS/Explicit is used to calculate the additional damping ratio of the first-order vibration modes. The feasibility of the finite element software to simulate the collision problem is verified. Based on the above research contents, the following conclusions can be drawn: (1) for the corrugated steel sheet rubber concrete model pier, the flat steel plate rubber concrete model pier and the rubber concrete clad model pier, with the increase of pendulum height, (2) when the falling height of pendulum is the same, the top displacement response of rubber-concrete covered pier is the largest, followed by flat steel plate rubber-concrete covered pier. The displacement response of the pier with corrugated steel plate rubber-concrete is the smallest. (3) the peak impact force of the model pier with different types of cladding is different, because of the local deformation of corrugated steel plate rubber-concrete piers, the effect of wave-shaped steel plate rubber-concrete cladding piers is the least. The impact force can be effectively prevented from growing too fast. (4) Waveform steel plate rubber concrete coating and steel plate rubber concrete coating are controlled by the local plastic deformation energy dissipation of the outer steel plate and the energy absorption of the inner layer rubber concrete to control the strain of the pier body. When the deformation of the outer plate is not stable, the local deformation energy dissipation of the steel plate is dominant, but when the local deformation of the outer plate is fully developed, the energy dissipation of the local deformation of the steel plate is dominant. (5) the maximum strain, displacement of pier top, impact point and acceleration of pier top obtained by finite element simulation are in agreement with the trend of test value, and the numerical value is slightly larger. It can be considered that the finite element software ABAQUS used in this paper is feasible to calculate the dynamic response of piers under impact load, and it is considered from the point of view of ensuring the safety of pier structure. The finite element calculation results are conservative. (6) for corrugated steel plate rubber-concrete coating and steel plate rubber-concrete coating, steel plate can not only serve as formwork, but also provide greater lateral stiffness. Especially for the corrugated rubber concrete coating, the vertical ripple increases the mechanical bite force of the inner rubber concrete and the outer steel plate, and the vertical wave plays the role of stiffening rib, and the lateral resistance is better, therefore, the vertical ripple increases the mechanical bite force of the inner rubber concrete and the outer steel plate, so the lateral resistance is better. The combination of corrugated steel plate or flat steel plate with rubber concrete can be used as a composite anti-collision protective layer for bridge piers, and the satisfactory construction and mechanical properties can be obtained.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U444;U443.26

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