翻转动能对基础隔震剪力墙结构高宽比限值的影响分析  

Analysis on the influence of overturning kinetic energy to Height-width Limit Ratio of Base-isolated Shear-wall Structure

作　　者：赖正聪[1,2] 潘文 白羽[1,2] 叶燎原 LAI Zhengcong;PAN Wen;BAI Yu;YE Liaoyuan(School of Architectural Engineering,Kunming University of Science and Technology,Kunming 650500,China;Earthquake Engineering Researching Center of Yunnan,Kunming 650500,China;Yunnan Normal University,Kunming 650500,China)

机构地区：[1]昆明理工大学建筑工程学院,昆明650500 [2]云南省抗震工程技术研究中心,昆明650500 [3]云南师范大学,昆明650500

出　　处：《振动与冲击》2019年第5期146-154,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51368027; 51168024)

摘　　要：针对上部结构整体刚度较大的基础隔震剪力墙结构体系,通过将上部剪力墙结构简化为刚体得到能够考虑结构翻转动能的两自由度基础隔震简化模型,并以此为分析对象,建立体系振动微分方程。采用复模态方法进行解耦变换,分析结构平动及隔震层翻转角位移的频响特性。在此基础上提出了考虑上部结构翻转动能影响动力倾覆分析方法,并推导了高宽比限值的动力法计算公式。通过对比分析动力法及等效静力计算结果,得出以下结论:上部结构翻转动能对基础隔震高层剪力墙结构以支座不受拉为控制条件的高宽比限值的影响不容忽视;所提出的动力倾覆分析法较仅考虑平动动能的等效静力法更为准确,且更偏于安全;等效静力法相对于动力法计算结果的偏差随着地震烈度、隔震结构周期、场地卓越周期的增大而减小,随隔震层水平等效阻尼比的增大而增大;在其他设计条件不变的情况下,减轻上部结构质量、增大隔震支座总竖向刚度,对基础隔震剪力墙结构高宽比限值的提高是有利的;分析基础隔震剪力墙结构高宽比限值时,应当充分考虑场地条件、地震分组、结构周期、阻尼比等因素的影响。Aiming at the base-isolated shear wall structure system with larger overall stiffness of the superstructure,a simplified model of two-degree-of-freedom base isolation was obtained by simplifying the upper shear wall structure as a rigid body,which can take account of the kinetic energy of the structure overturning.The vibration differential equation of the system was established.The complex modal method was used for decoupled transformation to analyze the frequency response characteristics of the translational motion of the structure and the reversal angular displacement of the isolation layer.On this basis,a dynamic overturning analysis method considering the effect of the overturning kinetic energy of the superstructure was put forward,and the dynamic calculation formula of the limit value of height-width limit ratio was derived.By comparing the results of dynamic method and equivalent static analysis,it was concluded that the influence of the turnover kinetic energy of the superstructure on the height-width ratio limit value of the base-isolated high-rise shear wall structure under the condition that the bearing is not subjected to tension should not be ignored;The dynamic capsizing method proposed in this paper is more accurate and safer than the equivalent static method which only considers translational kinetic energy.The deviation between equivalent static method and dynamic method decreases with the increase of seismic intensity,isolation structure period and site predominant period,and increases with the increase of horizontal equivalent damping ratio of isolation layer.Reducing the mass of the superstructure and increasing the total vertical stiffness of the isolation bearing are beneficial to the improvement of the limit value of the ratio of height to width of the base-isolated shear wall structure.As for the analysis of the limit ratio value,the influence of site condition,seismic grouping,structural period and damping ratio should be fully considered.

关 键 词：剪力墙结构 基础隔震 倾覆 高宽比限值 翻转动能 复模态分析 

分 类 号：TU352.1[建筑科学—结构工程] TU355