某超高层钢管混凝土柱框架-核心筒结构的抗震设计

RESEARCH OF SEISMIC DESIGN FOR A HIGHRISE CFT FRAME-TUBE STRUCTURE

通过一超高层钢管混凝土框架-钢筋混凝土核心筒结构的抗震设计,给出结构的抗震性能分析结果及薄弱环节的加强措施。抗震设计除采用常见的小震分析方法和指标外,还研究中震下构件抗力与地震作用的关系,并与大震动力弹塑性时程分析的损伤情况进行比较。通过抗震设计发现,结构的层间位移角变化率反映弯曲型变形结构的竖向刚度变化,刚度急剧变化处的剪力墙在大震下易出现损伤;构件抗震富余承载力与地震效应之比揭示了结构的薄弱环节,钢管混凝土柱具有较高的富余抗力,而核心筒底部在拉弯内力下该比值偏低,大震下核心筒出现明显受拉损伤。

A seismic design for a suppr highrise CFT frame-reinforced concrete tube structure is carried out to study its seismic behaviors. In addition to common evaluation indices for frequent earthquake action, seismic capacity of structural members is analyzed for the occasional earthquake action. The results are compared with those of the dynamic elastoplastic time-history analysis for a rare earthquake. The seismic design shows that the story drift ratio, demonstrating the vertical stiffness variation for flexure-deformation structure, accurately predicts probable damage of the shear walls. Low ratio of abundant capacity to earthquake effect is inclined to be fragile position. The CFT columns of the structure have high magnitude of the ratio. However, the ratio is low for bottom of the concrete core tube where obvious tension damage occurs under the rare earthquake input.