钢骨混凝土桥墩静动响应研究

发布时间：2018-04-09 19:34

本文选题：钢骨混凝土桥墩　切入点：撞击力　出处：《南京工业大学》2015年硕士论文

【摘要】：钢骨混凝土结构是在钢筋混凝土里面插入型钢或者型钢骨架而形成的组合结构体系。与普通钢筋混凝土结构相比,钢骨结构具有整体性好,强度高,承载力强、抗动力性能好、施工快捷等优点。基于这些优点,不管在建筑结构还是桥梁工程中都会流行起来。随着钢骨结构的大面积应用,其性能也得到了学者和研究设计人员的广泛关注和研究。随着我国高速公路工程的迅猛发展,桥梁建设规模也不断增长。不管是跨江河桥梁还是跨线桥梁,都是公路交通运输系统中的瓶颈。近年来全国乃至全世界,经常发生桥梁被撞事故,造成桥梁损坏、垮塌等严重后果。目前有关桥墩的动强度设计这一方面的研究较少。本文共设计2根钢筋混凝土桥墩和5根钢骨混凝土桥墩(包括3根角钢混凝土桥墩和2根槽钢混凝土桥墩),分别进行静力集中力加载试验和侧向撞击试验,以研究钢骨混凝土桥墩在静力集中荷载和撞击荷载作用下的性能,主要研究内容和成果如下：1、通过对一组钢筋混凝土梁和缓冲装置分别进行静力和撞击试验,并在部分梁上加缓冲装置,分析梁和缓冲装置的性能,对静动响应关系进行试验基础研究。得到了梁的钢筋应变曲线、箍筋应变曲线、混凝土应变曲线、位移曲线和缓冲装置压缩曲线。2、分析试验梁所得曲线,对静动荷载下的响应进行对比,可见动态荷载作用下梁各部分响应要高于静态荷载下的,对构件进行动强度设计时应考虑动响应；将缓冲装置的静动压缩曲线进行对比,可见缓冲装置在动荷载作用下吸收的能量比静荷载作用下的多；将缓冲装置吸收的能量扣除后构件的应变与同等撞击能量作用下的构件对比,可见缓冲装置对撞击荷载的特性和构件的动力响应均有较显著的影响。由于静动关系具有相似性,为后续研究桥墩的静动响应关系及缓冲装置对动力响应的影响提供参考,作为桥墩分析的基础。3、通过对钢骨混凝土桥墩进行静动对比试验。对静态荷载作用下的荷载位移曲线进行分析,可见钢骨改善了桥墩的性能,提高了桥墩的极限承载能力,很大程度上抑制裂缝的出现和发展。对撞击荷载作用下的钢筋应变进行分析,缓冲装置显著降低了钢筋应变峰值；将动应变的峰值与静力作用下的应变进行比较,研究应变放大系数的一般规律。4、分别研究静力作用下的位移和动力作用下的位移响应,运用微分方程,将撞击力分别等效为阶跃力和三角波荷载,得到位移响应表达式；再将静动响应进行对比,得到动力位移放大系数的计算公式,分析了影响位移响应和位移放大系数的影响因素,将理论所得位移放大系数与试验所得结果相比,符合较好,为研究桥墩动力强度设计提供一定的研究基础
[Abstract]:Steel reinforced concrete (SRC) structure is a composite structure formed by inserting steel or steel skeleton into reinforced concrete.Compared with the common reinforced concrete structure, the steel structure has the advantages of good integrity, high strength, strong bearing capacity, good dynamic resistance and quick construction.Based on these advantages, both in the building structure and bridge engineering will become popular.With the wide application of steel structure, its performance has been paid more and more attention by scholars and designers.With the rapid development of highway engineering in China, the scale of bridge construction is also increasing.Both river bridge and bridge beam are the bottleneck of highway transportation system.In recent years, bridges are often hit by accidents all over the world, resulting in bridge damage, collapse and other serious consequences.At present, there are few researches on the dynamic strength design of bridge piers.In this paper, two reinforced concrete piers and five steel reinforced concrete piers (including 3 angle steel concrete piers and 2 channel steel concrete piers) are designed, and the static concentrated load test and lateral impact test are carried out respectively.In order to study the behavior of steel reinforced concrete pier under static concentrated load and impact load, the main contents and results are as follows: 1. The static and impact tests of a group of reinforced concrete beams and buffers are carried out respectively.A buffer device is added to some of the beams to analyze the performance of the beam and the buffer device, and the static and dynamic response relationship is studied.The reinforced strain curve, stirrups strain curve, concrete strain curve, displacement curve and compression curve of buffer are obtained. The curves obtained from the test beam are analyzed and the responses under static and dynamic loads are compared.It can be seen that the response of each part of the beam under dynamic load is higher than that under static load, the dynamic response should be considered when designing the dynamic strength of the member, and the static and dynamic compression curve of the buffer device should be compared.It can be seen that the buffer device absorbs more energy under the dynamic load than under the static load, and the strain of the member after deducting the energy absorbed by the buffer device is compared with that of the member under the same impact energy.It can be seen that the buffer device has a significant effect on the characteristics of the impact load and the dynamic response of the member.Due to the similarity of static and dynamic relationships, this paper provides a reference for further study on the static and dynamic response of pier and the influence of buffer device on dynamic response. As the basis of pier analysis, the static and dynamic tests of steel reinforced concrete pier are carried out.By analyzing the load-displacement curve under static load, it can be seen that steel can improve the performance of piers, improve the ultimate bearing capacity of piers, and restrain the appearance and development of cracks to a great extent.The strain of steel bar under impact load is analyzed, and the peak value of steel bar strain is significantly reduced by the buffer device, and the peak value of dynamic strain is compared with the strain under static force.The general law of strain magnification factor is studied. The displacement response under static force and dynamic action is studied respectively. By using differential equation, the impact force is equivalent to step force and triangular wave load, and the displacement response expression is obtained.By comparing the static and dynamic responses, the formula of dynamic displacement magnification factor is obtained, and the influencing factors of displacement response and displacement magnification factor are analyzed. Compared with the experimental results, the theoretical displacement magnification coefficient is in good agreement with the experimental results.It provides a certain research foundation for studying the dynamic strength design of bridge pier.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U443.22

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