远场长周期地震动作用下高层框剪结构地震反应分析

选取3条远场长周期地震动和2条普通地震动,在比较其能量特性的基础上,采用ETABS软件建立两栋高层框剪结构的有限元模型。对比研究了地震动类型和结构基本周期对结构弹性地震反应的影响规律。结果表明:远场长周期地震动对高层框剪结构的地震反应具有放大作用;在其作用下结构的层间剪力、楼层位移和层间位移角明显大于普通地震动作用下的结果。远场地震动作用下结构的最大层间位移角出现在中下部楼层,且明显超出现行规范1/800的限值要求。普通地震动作用下结构的最大层间位移角出现在中上部楼层,能够满足规范限值要求。随着结构基本周期的增加,远场长周期地震动作用下结构的地震反应随之增大;普通地震动作用下结构的基底剪力、顶层位移逐渐增大;最大层间位移角略有下降、出现的楼层明显上移;顶层位移对长周期地震动、结构基本周期最为敏感。建议在高层结构抗震设计时进行远场长周期地震动作用下结构的抗震性能验算;且将结构位移作为重要的控制指标。

Analysis on seismic response of high-rise frame-shear wall structure under far-field long-period ground motions

Three far-field long-period ground motions and two general ground motions are chosen. Based on energy property comparison, the finite element models of two high-rise frame-shear wall structures are established by ETABS software, and the influences of ground motion type and basic vibration period on seismic response of structures are studied comparatively. The results show that far-field long-period ground motion has amplification effect on the seismic response of high-rise frame-shear wall structures, the interlayer shears, floor displacements and interlayer displacement angles are significantly greater than the result under general ground motion; the maximum interlayer displacement angles under far-field long-period ground motions appeared on the lower floors are obviously beyond the 1/800 limit requirements, but the maximum interlayer displacement angles under general ground motions appeared on the upper floors can meet the codes; With the increase of the basic vibration period, the seismic response of structures under far-field long-period ground motions increase accordingly, the base shear and the top floor displacement increase under general ground motions, but the maximum interlayer displacement angle decrease slightly and the floor appeared shift upward; The top floor displacement is most sensitive to long-period ground motion and basic vibration period, the seismic performance calculation of the high-rise structure under the action under far-field long-period ground motion and the structural displacement as an important control indicator are proposed.