超高层建筑竖向地震响应的特点与应对方法  

Characteristics and countermeasures of vertical seismic response for super high-rise buildings

作　　者：王明珉 王源 朱立刚[1] 汪洋[1] Wang Mingmin;Wang Yuan;Zhu Ligang;Wang Yang(ARUP,Shanghai 200092,China)

机构地区：[1]奥雅纳工程咨询(上海)有限公司

出　　处：《建筑结构》2019年第22期34-38,45,共6页Building Structure

摘　　要：计算了6个不同高度和不同结构体系的超高层建筑模型的竖向自振周期和竖向地震响应;分析了超高层建筑竖向构件和水平构件的竖向地震动响应特征。研究发现,超高层建筑水平自振周期远大于场地特征周期,而竖向自振周期则与场地特征周期接近,竖向振动响应得到放大。根据设计反应谱,对于各种抗震设防烈度,结构总竖向地震作用标准值FEvk都至少是结构总水平地震作用标准值FEk的2. 44倍。进而提出描述超高层建筑受到竖向地震全过程的4个概化模型,并指出规范简化算法的局限性。提出竖向地震作用对P-Δ效应与P-δ效应的放大主要体现在P值增大,使得"重力二阶效应"变成"重力与竖向地震响应共同作用下的二阶效应"。采用时程分析法研究了水平构件振动加速度响应,提出二次振动和竖向构件错动对水平构件振动响应有显著影响。分析了采用振型分解法计算超高层建筑竖向地震响应时质量参与系数偏低的原因,并指出当结构高度超过某一数值时,竖向地震作用下的结构第一阶振型会从竖向振动转变为水平摆动。The vertical natural period and the vertical seismic response of models of six super high-rise buildings with different heights and structural systems were calculated;the vertical ground motion response characteristics of vertical members and horizontal members of super high-rise buildings were analyzed. The study shows that the horizontal self-vibration period of super high-rise buildings is much larger than the site characteristic period,while the vertical natural period is close to the site characteristic period,so the vertical vibration response is amplified. According to the design response spectrum,for all kinds of seismic fortification intensity,the standard value of vertical seismic action FEvkis at least 2. 44 times of the structural total horizontal seismic action value FEk. Furthermore,four generalized models describing the whole process of super-high-rise buildings subjected to vertical earthquakes were proposed,and the limitations of the simplification method in Chinese code were pointed out. It is proposed that the vertical seismic action amplifies the P-Δ effect and the P-δ effect mainly due to the increase of the P value,so that the "gravity second-order effect"becomes the"second-order effect under the joint action of gravity and vertical seismic response". The time-history analysis method was used to study the vibration acceleration response of horizontal members. It proposed that the secondary vibration and different displacement of vertical components have a significant influence on the vibration response of horizontal members.The reason why the mass participation coefficient is low when calculating the vertical seismic response of super high-rise buildings by vibration mode decomposition method was analyzed. It pointed out that when the height of the structure exceeded a certain value,the first mode shape of the structure under vertical earthquake would turn from vertical vibration to horizontal swing.

关 键 词：竖向地震 竖向自振周期 重力二阶效应 二次振动 楼板振动 质量参与系数 

分 类 号：TU318.1[建筑科学—结构工程]