Research On Elastoplastic Performance Of Tall Building With Arch Transfer Story

The arch transfer story is a new type of transfer story form, which has major advantage such as strong stiffness, light weight, large span, and can supply more useful space for owner. The key research work in this paper is the elasto-plastic analysis of tall building with arch transfer story under the action of severe earthquake, so elasto-plastic dynamic time history analysis and static elasto-plastic analysis (Pushover) are adopted to research the sesmic response of the structure under the action of severe earthquake.On the basis of existing research about arch transfer story, the mechanical properties of arch transfer story, girder transfer floor and truss transfer story subjected to vertical load and frequent earthquake action are analyzed by PKPM serial software developed in China Academy of Building Research in this paper, and the structure form, mechanical behavior and reinforcement of the three types of transfer stories are compared. The results indicate that the mechanical property of arch transfer story may be more rational than that of girder transfer and truss transfer story, and the arch transfer story may be more practical in actual engineering than the other two transfer stories.In this paper, the basic principles of elasto-plastic dynamic time history analysis and static elasto-plastic analysis are introduced in detail, and the analysis of tall building with arch transfer story is conducted by EPDA&PUSH module of PKPM serial software developed in China Academy of Building Research.The results indicate that under the action of severe earthquake, the arch transfer story shows good integrity and the small storey displacement, the lower chord, bottom column and the column in the adjacent story above the transfer story are easy to yield and produce plastic hinges, and the adjacent stories of transfer story are weak, which should be strengthened. For the purpose of rational plastic hinge distributed in the structure , and no collapse under the action of severe earthquake, it may be suggested that the reinforcement of the bottom columns should be increased with the seismic fortification intensity 7, and the coefficient of enhancement of bearing capacity is 1.3(site of categoryâ… ), 1.9(site of categoryâ…¡), 2.2(site of categoryâ…¢andâ…£); meanwhile it may be proposed that the coefficient of enhancement of bearing capacity of columns in the adjacent story above the transfer story is 1.25, and that of the lower chord is 3.5. If the arch transfer story want to meet the needs of design in zone with the seismic fortification intensity 8 or above, the coefficient of enhancement of bearing capacity must be no less than 2.9 for bottom columns, and 1.5 for the columns in the adjacent story above the transfer story, at that time, the reinforcement ratio of bottom column does not meet specification. It has been recommended that the bottom column may adopt steel reinforced concrete(SRC), which is exspensive. As a result, if the structure with arch transfer story employs reinforced concrete, it has been suggested that the structure may not be adopted in zone with the seismic fortification intensity 8 or above,and may be avoided to establish the structure on the soft foundation (site of categoryâ…£). The conclusions of pushover analysis in this paper are in agreement with that of elastic-plastic dynamic time history analysis.At last, the design requirements of arch transfer story are presented in this paper, which could be used as a reference for the design of the structure.