摘要
大底盘结构在竖向刚度突变处震害严重,采用层间隔震体系能有效解决底盘和塔楼间刚度及质量突变的问题。已有研究对层间隔震结构进行了大量的数值分析,但相应的振动台试验研究缺乏,且塔楼偏置的大底盘层间隔震结构平扭耦合效应研究未见报道。因此为了指导工程抗震设计,研究了塔楼偏置的大底盘层间隔震结构的地震响应和平–扭耦合效应。首先,建立一个位于8度设防区具有典型工程应用意义且塔楼偏置的大底盘结构(单塔楼),其底盘为2层,塔楼为6层,塔楼与底盘的平面面积比为1∶2.4,塔楼高宽比为1∶3,符合大底盘结构的受力特征和条件;接着,对其进行简化和缩尺并制作模型;最后,进行了双向振动台试验与数值分析对比。试验得到了模型各楼层的加速度和层间位移。结果表明:采用层间隔震技术,塔楼各层加速度和层间位移减震效果均显著,在0.60g作用下,减震率(Y向)分别为83.13%和81.18%以上;底盘加速度响应不减少反而增加,减震率(Y向)处于–12.69%～–24.07%;底盘层间位移减震率(Y向)在15.53%～17.15%,减震效果差;进一步分析得,模型在0.60g作用下塔楼仍处于弹性,而底盘在0.40g作用下就进入了弹塑性,且底盘第2层位移明显大于第1层。基于振动台的试验结果验证了数值模拟的准确性,进一步分析了结构的平–扭耦合效应。结果表明,与抗震模型相比,层间隔震底盘扭转角减少2/3,隔震层扭转响应较大但不向塔楼传递,塔楼层间扭转角趋于零,塔楼与底盘的扭转耦联效应不明显,从而塔楼偏置的大底盘单塔楼建筑采用层间隔震形式时,可有效降低结构的扭转效应。
Severe seismic damage can be occurred in the position of significant changes of the vertical stiffness of the large chassis structure,and the mid-story isolation system can effectively solve the problem of significant changes of stiffness and mass between the chassis and the tower.A large number of numerical analysis studies have been conducted to investigate the performance of midstory isolation structure.However,there has been a lack of experimental studies on mid-story isolation structure,and the study of the lateral–torsional coupling effect of the mid-story isolation structure with large chassis and eccentric tower has not been reported.Therefore,in order to guide the seismic design of the project,seismic response and the lateral–torsional coupling effect of the midstory isolation structure with large chassis and eccentric tower are studied.A large chassis structure(single tower)with significance of typical engineering application and eccentric tower is established at the zone of fortification intensity 8,in which the chassis has 2 floors and the upper tower has 6 floors,the plane area ratio of the upper tower to the chassis is 1:2.4 and the ratio of the tower height to the tower width is 1:3,I that is consistent with the typical features and conditions of such large chassis structure.According to this prototype structure,the simplify and the scaled model is built.A shaking table test and a numerical analysis are conducted by two-dimension ground motion input,and compared the results of the shaking table test and the numerical analysis.The acceleration and story drift of each story of the model are obtained.The experimental results show that the seismic response of the structure is reduced obviously by using mid-story isolation technology.Through the analysis of experimental data,it is known that the ratio of acceleration reduction and the ratio of story drift reduction for upper tower are 83.13%and 81.18%or more(Y-dir)when peak ground acceleration is 0.60g.However,the acceleration response of the chassi
作者
吴应雄
陆剑峰
赵欣
林友勤
WU Yingxiong;LU Jianfeng;ZHAO Xin;LIN Youqin(College of Civil Eng.,Fuzhou Univ.,Fuzhou 350116,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2018年第6期48-55,共8页
Advanced Engineering Sciences
基金
国家自然科学基金资助项目(51778149)
关键词
大底盘结构
塔楼偏置
层间隔震
振动台试验
平–扭耦合
large chassis structure
eccentric tower
mid-story isolation
shaking table test
lateral–torsional coupling
