Mega steel frame-prestressed composite bracing structure is a new lateral resistant system in the modern high rise buildings, which is designed on the elastic response spectrum for the wind-resistant and seismic design and then studied by using the Pushover analytic method based on two different lateral loading patterns of uniform distribution and inverse triangle distribution in order to investigate the horizontal elastic lateral stiffness, the mechanical characteristic of cable, the yield mechanism when plastic hinge occurring in the members, and the overall seismic performance as well. The results indicate that the horizontal limit bearing capacity and lateral stiffness under inverse triangle distribution are less than that under uniform distribution. The maximum tension stress of cables is less than the yield strength of 650MPa under these two loading patterns. With the increasing horizontal load, the tension stress for one part of cables gradually decreases up to zero, but the tension stress for another part of cables further increases on the basis of the pretensioned stress. The failure modes of all members of the mega steel frame-prestressed composite bracing structure under lateral loads are as follows: web members of giant beam appear to yield at first, and then the supports between giant column limbs, giant A-shape steel brace truss, floor beams in order. Meanwhile, the seismic design based on elastic response spectrum is unsuitable for this dual lateral load resisting system and the theory of performance-based seismic design should be adopted to obtain the reasonable and economic structure.%巨型钢框架-预应力复合支撑体系是现代高层建筑中的一种新型抗侧体系,本文基于弹性反应谱对其进行抗风、抗震设计,然后在倒三角型分布和均匀分布的两种水平荷载加载模式下进行Pushover分析,研究出该结构体系在不同水平加载模式下的破坏机理,考察其抗侧刚度、拉索受力特征及构件先后出现的屈服机制和结构的整体抗震性能.研究表明,倒三角型分布的结构水平极限荷载和弹性抗侧刚度都小于均匀分布得到的结果；拉索的最大拉应力均未达到屈服强度650MPa,并且随着水平荷载的逐渐增加,一部分拉索拉应力逐渐减少,直至退出工作,而另一部分拉索则在预拉应力的基础上拉应力进一步增大；巨型钢框架-预应力复合支撑体系各构件的破坏顺序为巨型梁腹杆最先出现屈服,而后依次分别是巨型柱肢间的支撑、巨型八字支撑、巨型柱肢间的楼层梁；对该结构体系不能再沿用弹性设计反应谱的方法进行抗震设计,而应采用基于建筑抗震性能化的理念来进行合理、经济的抗震设计.
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