大震作用下带拱式转换层高层结构动力弹塑性分析

Dynamic analysis of elastoplastic performance of tall building with arch transfer floor subjected to severe earthquake

针对大震作用下带拱式转换层高层结构的地震反应,分析了该结构楼层侧移、楼层剪力、薄弱部位及塑性铰分布等,表明:转换层相邻上下两层及转换层下弦杆跨中为结构薄弱部位.为了在罕遇地震作用下,结构塑性铰能够合理分布,达到"大震不倒",对该结构薄弱部位应采取加强措施,并对此进行了动力弹塑性时程分析,结果表明,加强后结构薄弱部位转移到转换层上部楼层中,且结构塑性铰分布较合理,由此提出该结构底部柱承载力增大系数:当Ⅰ类场地时为1.3,Ⅱ类场地时为1.9,Ⅲ类和Ⅳ类场地时为2.2;转换层相邻上部柱承载力增大系数为1.25;转换层下弦杆跨中承载力增大系数为3.5.

On the basis of earthquake response of tall building with arch transfer floor subjected to severe earthquake, the storey lateral displacement, the storey shearing force, the weak location and plastic hinge of distribution have been analyzed, which indicates that the adjacent storeys above and under the transfer floor, and the midspan of the lower chord of the transfer floor are easy to be weak location. For the purpose of rational distribution d plastic hinge and no collapse under the action of severe earth- quake, the weak locations have been reinforced of the structure, and the dynamic elastoplastic time analysis has been advanced. The result may indicate that the weak location has been transferred to up- per storeys of the transfer floor, and the plastic hinges in the structure may be distributed more ratio- nally after reinforcing of the structure. From this, it has been suggested that the reinforcement coefficient of bearing capacity may be 1.3 （site of categoryⅠ ）, 1.9 （site of category Ⅱ ）, 2.2 （site of catego- ry Ⅲ andⅣ ）, the reinforcement coefficient of columns in the adjacent storey above the transfer floor may be 1.25, as well as that of the midspan of lower chord may be 3.5.