近断层地震动具有独特的上盘效应、破裂方向性效应和速度脉冲特征。本文分组考察具有这些运动特征的地震动对短肢剪力墙高层建筑结构地震反应的影响。选择台湾集集近断层地震动记录作为地震动输入,利用ANSYS软件对一幢12层短肢剪力墙结构建立空间杆件一壳元组合有限元模型,进行弹塑性时程分析。计算结果表明,近断层地震动上盘效应和破裂方向性效应明显增大短肢剪力墙结构体系的地震反应,短肢剪力墙高层结构的最大层间位移角发生在中部第5层,为0.98%,说明该结构已经达到中等破坏状态;脉冲型地震动效应与结构周期长短密切相关,对长周期结构脉冲效应显著。
Near-fauh ground motions have the distinct characteristics of hanging wall effect, rupture directivity effect, and velocity pulse-like motion. The present paper examines the influence of the ground motions with these characteristics on the seismic responses of the highrise building structure with short-limb walls. Near-fauh ground motion recordings from the same earthquake event, i.e. Chi-Chi, Taiwan earthquake (Sep. 21, 1999), are selected as an input. The ANSYS software is used to establish a 3D member-shell combined finite element model for one 12-story highrise building structure with short-limb walls, and the elasto-plastic time history analysis of the structure is implemented. The numerical results illustrate that the hanging wall and the directivity effect amplify the seismic responses of the structural system with short-limb walls remarkably, and the maximum drift ratio of the structure occurs at the 5th story in the middle of the building, and attains 0.98%, which demonstrates that the building reaches medium damage state. Moreover, the effect of pulse-like ground motions depends highly on the structural period, and the pulse-like effect on the long-period structure is significant