Research On The Effect On Seismic Performance Of The Equivalent Stiffness Ratio To Structure With Beam Transfer Floor

Structures with beam transfer floor are widely used in high-rise buildings.Researchers at home and abroad have done a lot of studies on this kind of structures in recent years and got a large number of useful suggestions and conclusions.But the results of existing research on seismic performance of this kind of structure is not great perfect.Most of the study on how the transfer floor’s location affect the seismic characteristics of the structure mainly change the location of the transfer floor.This lead to the change of the key factor—the equivalent stiffness ratio which influence the mechanical characteristics of the structure.In order to study how the transfer floor’s position affect this kind of structure,in this paper the equivalent stiffness ratio remain unchanged,then transfer floors position are changed.When study the equivalent stiffness ratios effect on the mechanical characteristics of this kind of structure,in the majority of existing literatures usually by changing a single parameter to obtain different values of equivalent stiffness ratio.In this paper we obtain different values of equivalent stiffness ratio by changing four different parameters, and finally the results show that different values of equivalent stiffness ratio have different influences on the seismic performance of the structure.The content of this paper are:1.Applying the finite element analysis software SAP2000 to establish calculation model steming from the actual project.Response spectrum method is used to study the change of its seismic performance.Time history analysis method is used to calculate its base shear force,top displacement and acceleration,the distribution of base shear force between shear wall and frame pillar.2.By keeping the equivalent stiffness ratio unchanged,we change the location of transfer floor and establish different models.Response spectrum method is used to analyze these models to study how the location of transfer floor affect their seismic performance.3.When transfer floor is set at a fixed layer, by changing the section size of frame pillar,the thickness of shear wall above transfer floor, the thickness of score-tube shear wall under transfer floor.the cross section size of support beam located in transfer floor and the lower floors,sixteen different models are established. We use response spectrum method to analyze these models and to study how the different values of equivalent stiffness ratio affect their seismic performance.4.This paper also studies how the distribution of the hole in shear wall above transfer floor, the span-depth ratio of transfer beam, the length of shear wall within the span of transfer beam affect the internal force of transfer beam.5.Nine calculation models are established according to the change of transfer floors position and the different values of the equivalent stiffness ratio.Elastic time history analysis method is used to research the variation of storey shearing force, top displacement and acceleration of these models. The datas of internal force of transfer beam and frame pillar are extracted to study the characteristic of the internal force of the key members under the action of various seismic waves.