考虑土—结构相互作用下异形柱框架结构隔震性能分析

发布时间：2018-03-19 21:24

本文选题：异形柱　切入点：节点　出处：《辽宁工程技术大学》2013年博士论文　论文类型：学位论文

【摘要】：目前异形柱结构在我国有着广泛的应用,但异形柱构件截面形状不规则,纵筋配置也不对称,为提高异形柱结构抗震性能,应用隔震元件是有效途径之一；同时,在结构抗震设计中地基的处理上仍旧是以刚性假设为基础,而土层对地震波的过滤和放大作用是不能忽视的；因此考虑土-结构相互作用下,研究异形柱框架隔震结构的抗震性能具有一定的研究价值和实际意义。首先对12根钢筋混凝土异形柱进行低周往复荷载作用下抗震性能数值模拟研究,建立了L形截面、T形截面和十字形截面异形柱并考虑轴压比,柱肢尺寸,配箍率及截面配筋对各构件抗震性能的影响。结果表明异形柱破坏过程中经历的破坏形态、裂缝出现和延性性能与异形柱构件的轴向压力有很大关系,轴压比大的情况下,异形柱构件破坏较快,水平变形小,滞回面积较小即耗能能力差,裂缝也较晚出现；当轴压比小时,反而易出现裂缝,但异形柱构件变形能力较强延性较好,滞回曲线饱满即体现了异形柱构件延性好,耗能能力强,有较好的抗震性能。箍筋用量和截面尺寸的增加可以混凝土提高构件的延性。对3个钢筋混凝土异形柱框架节点进行了抗震性能数值模拟研究,对节点的延性、耗能能力、刚度退化等性能进行了分析；发现异形柱构件节点核心区箍筋在混凝土开裂前应力变化不大,混凝土开裂后失去抗剪能力,箍筋应力有很大增加,说明箍筋承担了大部分剪力,所以有必要在核心区配置相对数量的箍筋以防止节点核心区的提前失效。为提高异形柱框架结构的抗震性能,研究了以铅芯橡胶支座为主的隔震元件的吸能耗能机理；铅芯橡胶支座的阻尼力大、耗能能力强,但实验研究表明,当承受较大的水平位移荷载时,铅芯材料由于其塑性性能很难恢复原状,因此考虑在铅芯橡胶支座的基础上复合形状记忆合金材料(Shape Memory Alloy,简称SMA),根据实验研究得出了形状记忆合的超弹性力学性能,通过理论分析证明了形状记忆合金复合铅芯橡胶支座可以增加普通支座的恢复力,提高了支座的耗能能力,从而保证橡胶支座在发生较大剪切变形时仍然能够恢复到原位,达到更好的隔震效果。最后通过建立钢筋混凝土异形柱框架隔震结构模型,研究形状记忆合金复合铅芯橡胶支座对结构抗震性能的影响,重点考察了考虑土—结构相互作用该支座的减震性能；通过分析建筑物层间的位移、加速度、速度时程曲线,对比分析建筑物的最大相对位移和最大绝对位移发现：地震波的高频部分被隔震支座和地基土过滤掉,特别是作为地震波传播媒介的地基土,其高频滤波效应不容忽视。同时也说明了在刚性地基条件下对异形柱框架结构地震响应分析,与考虑土—结构相互作用的异形柱框架结构的地震响应是有所差别的：地基土的存在增加了结构的绝对位移,用刚性地基条件假设条件而不考虑土—结构相互作用的的影响而进行异形柱框架结构的抗震设计是偏于安全和保守的。
[Abstract]:At present, the special-shaped column structure is widely used in our country, but the section shape of the special-shaped column is irregular, longitudinal reinforcement configuration is asymmetric, in order to improve the seismic behavior of special-shaped column structure, the application of isolation is one of the effective ways; at the same time, the foundation treatment in the seismic design of structures is still in rigid assumptions and filtering the layer of seismic wave and the amplification can't be ignored; therefore, considering the soil structure interaction, it has certain research value and practical significance to study on the seismic behavior of special-shaped column frame isolated structure.
The first of 12 reinforced concrete columns were simulated and Numerical Study on seismic performance under low cyclic loading, L section was established, and the T shaped cross-section columns and axial compression ratio, limb length, stirrup ratio and reinforcement on the seismic performance of the components. The results show that the influence of through the failure process failure form of special-shaped column, has a lot of axial pressure cracks and the ductility of the special-shaped columns and the axial compression ratio is large, the special-shaped column damage level fast, small deformation, hysteretic energy dissipation capacity is smaller, the cracks also appeared later; but when the axial compression ratio of hours. Easy to crack, but the special-shaped column deformation capacity ductility, hysteretic curve is full that embodies the special-shaped columns have good ductility, energy dissipation capacity, has better seismic performance. Increasing the amount of stirrup and section size can coagulation The soil increasing ductility. On 3 reinforced concrete special-shaped column frame joints are analyzed by numerical simulation of seismic performance, ductility, energy dissipation capacity of joints, stiffness degradation performance was analyzed; found that the special-shaped columns node stirrups in concrete cracking stress changes little after concrete cracking lost shear capacity, stirrup stress has greatly increased, indicating the stirrups bears most of the shear, so it is necessary to configure in the core area of the relative number of stirrups to prevent the core region of node failure in advance.
In order to improve the seismic performance of special-shaped column frame structure, studied the isolation element to lead rubber bearing mainly absorbing energy dissipation mechanism; the damping force of the lead rubber bearing, high energy consumption, but the experimental study showed that when subjected to horizontal displacement of large load, the lead core material due to its hard plastic properties restitution, so consider on the basis of the lead rubber bearing on the composite shape memory alloy (Shape Memory Alloy, referred to as SMA), according to the experimental study on mechanical properties of superelastic shape memory alloy obtained by theoretical analysis proves that the shape memory alloy composite lead rubber bearing can increase ordinary bearing restoring force, improve the bearing capacity of energy dissipation, so as to ensure that the rubber bearing in large shear deformation can still be restored to the original position, to achieve a better isolation effect.
Finally, through the establishment of model of reinforced concrete special-shaped column frame structure of shape memory alloy composite lead rubber bearing on seismic performance, focusing on the bearing damping performance of soil structure interaction; through the analysis of building inter layer displacement, acceleration, velocity time curve, the maximum relative displacement analysis the building and the absolute maximum displacement that high-frequency seismic wave is filtered out of isolation bearing and foundation soil, especially as the foundation of seismic wave propagation media, the high frequency filtering effect can not be ignored. At the same time also shows that under the condition of rigid foundation on seismic response analysis of special-shaped column frame structure, special-shaped column frame with consideration the structure of soil structure interaction on the seismic response is different: the foundation soil has increased the absolute displacement of the structure, with a rigid foundation Assumptions without considering the influence of soil structure interaction and seismic design of frame structure with special-shaped columns is safe and conservative.

【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU375.4;TU352.12

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