既有建筑隔震加固中的双向受剪及防碰撞问题研究

发布时间：2018-06-29 20:11

本文选题：平扭耦联 + 铅芯橡胶隔震支座　；参考：《东南大学》2016年硕士论文

【摘要】：随着不规则结构和相邻结构的大量出现,对此类建筑进行隔震加固存在两方面问题：1.不规则的结构在地震作用下承受水平双向地震作用,使得隔震支座处于水平双向受剪状态,其表现出来的本构关系与单向受剪时完全不同,若按原有单向分析方法难以得到合理有效的结果；2.对抗震缝宽较小的既有相邻建筑进行隔震加固会增加其发生碰撞的可能性,因此,利用黏滞阻尼器连接相邻的隔震建筑以控制它们在地震作用下的动力响应,避免发生碰撞进而危及结构的安全。本文采用水平双向加载装置对LRB300和LRB400两种规格的铅芯橡胶支座进行了水平双向受剪的低周反复疲劳试验,获取了铅芯橡胶支座在水平双向1：1剪切变形时的试验数据,并对计算得到的水平刚度和等效粘滞阻尼比进行了比较分析。试验结果表明：铅芯橡胶支座的水平刚度和等效粘滞阻尼比随剪切变形的增加呈下降趋势,另外,在发生相同的水平方向剪切变形时,铅芯橡胶支座在双向受剪状态下的水平刚度和等效粘滞阻尼比均小于单向受剪时的情况。为了探讨铅芯橡胶支座双向耦合恢复力特性对偏心隔震结构动力响应的影响,本文利用结构分析软件对相关隔震工程算例进行了多遇地震下的弹性时程分析及设防地震下和罕遇地震下的弹塑性时程分析,分析结果表明：不考虑铅芯橡胶支座的双向耦合恢复力特性时,隔震结构的动力响应较大,但忽略双向耦合作用时会低估铅芯橡胶隔震支座的变形,这对于隔震层水平位移有较高限制要求的结构来说偏于不安全。为探讨阻尼器连接相邻隔震结构的动力响应,本文对黏滞阻尼器连接的相邻隔震结构分析模型分别进行了多遇地震下的弹性时程分析和罕遇地震下的弹塑性时程分析。在保证相邻隔震结构不发生碰撞的前提下,以相邻结构的底部剪力较小和阻尼器出力较小为优化目标,采用枚举法寻求出较优的阻尼系数和阻尼器布置位置,并探讨了阻尼器参数及布置位置的变化对相邻结构动力响应的影响。分析结果表明：选取合适的阻尼器参数及布置位置时,相邻隔震结构在地震作用下的顶层相向位移能得到有效的控制,从而避免其发生碰撞,保证结构在地震中的安全。
[Abstract]:With the emergence of irregular structures and adjacent structures, there are two problems: 1. Under the action of earthquake, the irregular structure is subjected to horizontal and bidirectional earthquake, which makes the isolated bearing in horizontal and bidirectional shear state. The constitutive relation of the structure is completely different from that of unidirectional shear. If it is difficult to obtain reasonable and effective results according to the original one-way analysis method. Seismic isolation reinforcement of existing adjacent buildings with small seismic joint width will increase the possibility of collision. Therefore, the viscous damper is used to connect adjacent isolated buildings to control their dynamic response under earthquake. Avoid collision and endanger the safety of the structure. In this paper, the low cycle repeated fatigue tests of LRB300 and LRB400 rubber bearings under horizontal and bidirectional shear are carried out by using horizontal bidirectional loading device, and the test data of lead-core rubber bearings under horizontal and 1:1 shear deformation are obtained. The horizontal stiffness and the equivalent viscous damping ratio are compared and analyzed. The experimental results show that the horizontal stiffness and equivalent viscous damping ratio of lead rubber bearings decrease with the increase of shear deformation. In addition, when shear deformation occurs in the same horizontal direction, The horizontal stiffness and equivalent viscous damping ratio of lead-rubber bearing are smaller than those of unidirectional shear. In order to investigate the effect of bidirectional coupling restoring force characteristics of lead rubber bearing on the dynamic response of eccentrically isolated structures, In this paper, the elastic time-history analysis and the elastic-plastic time-history analysis of seismic fortification and rare earthquake are carried out for the relevant isolated engineering examples by using the structural analysis software. The results show that the dynamic response of the isolated structure is larger when the bidirectional coupling restoring force of the lead-rubber bearing is not considered, but the deformation of the lead-rubber isolation bearing will be underestimated when the bidirectional coupling is ignored. This is unsafe for structures with high limit on horizontal displacement of isolation layer. In order to study the dynamic response of adjacent isolated structures connected with dampers, the analysis models of adjacent isolated structures connected with viscous dampers are analyzed by elastic time history analysis under frequent earthquakes and elastic-plastic time history analysis under rare earthquakes, respectively. On the premise of ensuring that the adjacent isolated structures do not collide with each other, the optimum targets are the smaller shear force at the bottom of the adjacent structure and the smaller output force of the dampers. The enumeration method is used to find out the optimal damping coefficient and the location of the dampers. The influence of damper parameters and location on the dynamic response of adjacent structures is discussed. The analysis results show that the displacement of the top layer of adjacent isolated structures can be effectively controlled when the appropriate damper parameters and location are selected, thus avoiding the collision and ensuring the safety of the structure in the earthquake.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU352.12

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