近断层地震动作用下LRB隔震连续梁桥纵向抗震性能研究
发布时间：2018-11-20 10:32
【摘要】：在远场地震动作用下铅芯橡胶支座(Lead Rubber Bearing,简称LRB)以其优异的减震效果而备受世人关注,而近断层地震具有诸如速度脉冲效应、上盘效应和破裂方向性效应等明显异于远场地震的运动特征,这些运动特征可能会影响到LRB隔震支座的减震效果,所以研究近断层地震动作用下LRB隔震桥梁的抗震性能具有一定现实意义。本文以铁路连续梁桥为研究对象,主要开展了以下几方面的研究:(1)在查阅大量国内外文献的基础上,分析了铁路桥梁的震害特征,评述了近断层地震动、桥梁减隔震技术、轨道约束作用和限位装置等相关研究现状;(2)针对连续梁桥制动墩纵向地震内力大的特点,提出在主墩处安装LRB隔震支座的减震方案。利用OpenSees软件建立相关动力计算模型,研究了LRB隔震支座的减震效果。结果表明,隔震后制动墩的位移及内力都大幅减小,最大减小幅度可达76.12%,LRB隔震支座表现出较好的减震效果。(3)通过比较发现,速度脉冲效应、上盘效应和破裂方向性效应等运动特征对LRB隔震连续梁桥纵向地震响应都有一定放大作用,其中速度脉冲效应的影响最大,方向性效应次之,上盘效应影响最小。(4)通过建立梁轨一体化动力计算模型,分别研究了竖向无载和有载两种工况下轨道对LRB隔震连续梁桥纵向地震响应的影响。结果表明,轨道对LRB隔震连续梁桥纵向的地震响应有一定减震作用,最大减小幅度可达25.50%,并且轨道在有载状态下的减震作用比无载状态下更显著。(5)针对LRB隔震连续梁桥减震效果好但主梁位移较大的特点,利用在边墩的墩梁间安置粘滞阻尼器来控制主梁位移,并提出选取粘滞阻尼器参数的原则。研究结果表明,粘滞阻尼器可大幅减小主梁位移,轻微减小主墩内力,同时还能保证边墩处于弹性范围内。
[Abstract]:Under the action of far-field ground motion, (Lead Rubber Bearing, (LRB) has attracted much attention for its excellent damping effect, while near-fault ground earthquake has the effect of velocity pulse. The upper disk effect and rupture directional effect are obviously different from the motion characteristics of far field earthquake, which may affect the shock absorption effect of LRB isolation support. Therefore, it is of practical significance to study the seismic behavior of LRB isolated bridge under near-fault seismic action. In this paper, the railway continuous beam bridge is taken as the research object, and the following researches are carried out: (1) on the basis of consulting a large number of literatures at home and abroad, the earthquake damage characteristics of railway bridges are analyzed, and the near-fault ground earthquakes are reviewed. The status quo of bridge isolation technology, track restraint and location-limiting devices; (2) according to the characteristics of large longitudinal earthquake internal force of brake pier of continuous beam bridge, a shock absorption scheme of installing LRB isolation support at main pier is put forward. Using OpenSees software to establish the related dynamic calculation model, the damping effect of LRB isolation bearing is studied. The results show that the displacement and internal force of the brake pier are greatly reduced after isolation, and the maximum reduction range can reach 76.12%. (3) through comparison, the velocity pulse effect is found. The upper disk effect and rupture directional effect have some magnification effect on the longitudinal seismic response of LRB isolated continuous beam bridge, among which the velocity pulse effect is the most important, and the directional effect is the second. (4) the influence of track on longitudinal seismic response of LRB isolated continuous beam bridge is studied by establishing the integrated dynamic calculation model of beam and rail. The results show that the track has a certain damping effect on the longitudinal seismic response of LRB isolated continuous beam bridge, and the maximum reduction range can reach 25.50. Moreover, the seismic absorption of track is more significant than that of non-load state. (5) aiming at the characteristics of LRB isolated continuous beam bridge with good damping effect but large displacement of main beam, the displacement of main beam is controlled by installing viscous dampers between piers and beams of side piers. The principle of selecting the parameters of viscous dampers is put forward. The results show that the viscous damper can greatly reduce the displacement of the main beam, slightly reduce the internal force of the main pier, and ensure that the side pier is in the elastic range.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55
本文编号：2344672
[Abstract]:Under the action of far-field ground motion, (Lead Rubber Bearing, (LRB) has attracted much attention for its excellent damping effect, while near-fault ground earthquake has the effect of velocity pulse. The upper disk effect and rupture directional effect are obviously different from the motion characteristics of far field earthquake, which may affect the shock absorption effect of LRB isolation support. Therefore, it is of practical significance to study the seismic behavior of LRB isolated bridge under near-fault seismic action. In this paper, the railway continuous beam bridge is taken as the research object, and the following researches are carried out: (1) on the basis of consulting a large number of literatures at home and abroad, the earthquake damage characteristics of railway bridges are analyzed, and the near-fault ground earthquakes are reviewed. The status quo of bridge isolation technology, track restraint and location-limiting devices; (2) according to the characteristics of large longitudinal earthquake internal force of brake pier of continuous beam bridge, a shock absorption scheme of installing LRB isolation support at main pier is put forward. Using OpenSees software to establish the related dynamic calculation model, the damping effect of LRB isolation bearing is studied. The results show that the displacement and internal force of the brake pier are greatly reduced after isolation, and the maximum reduction range can reach 76.12%. (3) through comparison, the velocity pulse effect is found. The upper disk effect and rupture directional effect have some magnification effect on the longitudinal seismic response of LRB isolated continuous beam bridge, among which the velocity pulse effect is the most important, and the directional effect is the second. (4) the influence of track on longitudinal seismic response of LRB isolated continuous beam bridge is studied by establishing the integrated dynamic calculation model of beam and rail. The results show that the track has a certain damping effect on the longitudinal seismic response of LRB isolated continuous beam bridge, and the maximum reduction range can reach 25.50. Moreover, the seismic absorption of track is more significant than that of non-load state. (5) aiming at the characteristics of LRB isolated continuous beam bridge with good damping effect but large displacement of main beam, the displacement of main beam is controlled by installing viscous dampers between piers and beams of side piers. The principle of selecting the parameters of viscous dampers is put forward. The results show that the viscous damper can greatly reduce the displacement of the main beam, slightly reduce the internal force of the main pier, and ensure that the side pier is in the elastic range.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55
【共引文献】
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1 宗周红;夏坚;徐绰然;;桥梁高墩抗震研究现状及展望[J];东南大学学报(自然科学版);2013年02期
，本文编号：2344672
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