Torsional Displacements in Base-Isolated Buildings
Torsional Displacements in Base-Isolated Buildings
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基础隔震建筑物的扭转位移
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
J. Kelly
中科院分区：
文献类型：
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作者：
R. S. Jangid;J. Kelly
分析了扭转耦联对基础隔震结构地震反应的影响。隔震结构被建模为一个刚性甲板上的轴向不可扩展的轴承支持。推导了系统弯扭耦合响应的运动控制方程。系统的偏心率由统一建筑规范（UBC）规定。研究了隔震体系在不同结构形式、不同隔震阻尼、不同扭振频率与水平频率之比组合下的位移响应。在各种近断层和其他地震地面运动下的隔震结构的反应进行了比较，通过使用反应谱分析得到。在反应谱分析中，对几种模态组合规则的精度进行了评价。结果表明，扭转耦合对隔震结构的响应有一定的影响，但如果隔震支座的布置使扭转频率大于横向频率，扭转耦合对隔震结构响应的影响就会减小，通常的模态组合规则也能很好地发挥作用。在这种情况下，由扭转引起的附加隔振器位移的UBC静力公式是保守的。
An analytical study of the effects of torsional coupling on the seismic response of a base-isolated building is presented. The isolated structure is modeled as a rigid deck supported on axially inextensible bearings. The governing equations of motion for the coupled lateral-torsional response of the system are derived. The eccentricity in the system is that specified by the Uniform Building Code (UBC). The displacement response of the isolated system with different combinations of building configuration, isolation damping, and the ratio of uncoupled torsional to lateral frequency of the system is investigated. The response of the isolated structure under a variety of near-fault and other earthquake ground motions is compared to that obtained by use of response spectrum analysis. In the response spectrum analysis the accuracy of several modal combination rules is evaluated. It is shown that torsional coupling can influence the response of the isolated structure, but if the layout of the isolation bearings is such that the torsional frequency is larger than the lateral frequency, the effect is reduced and the usual modal combination rules work well. It is also shown that in this case, the UBC static formula for the additional isolator displacements due to torsion is conservative.