Collapse Mechanism Research On Complacated High-rise Building With Transfer Girder

In order to meet the function of structure, we usually set transfer floor in high-rise building which means lateral force-resistance members are discontinuousness and stiffness is uneven in vertical..Structure appears weak storey under seismic force.It is harmful to anti-seismic.Girder transfer has more advantages than other types of transfer structure,and the girder transfer floor is used widely.It has a large development space in the future.While quite a lot of questions urBuildingt to be solved.In this paper, the design method of structure with transfer story and antiseismic performance analysis are systematically introduced.Take a specific project with transfer story as example, three different ratios of equivalent lateral stiffness of the stories above and below the transfer story are performed by response spectrum and time-history analysis by using SATWE. Study on the influence of the different ratios .Analysis results show that: hole on the vertical elements can significantly affect the stiffness of the structure,while adjust the section size is not obvious. In practical projects, vertical construction member with open hole is unavoidable, so should pay more attention for the hole processing ; the increase of lateral stiffness ratio influences the aseismic performance of structure which goes against structure seismic.A high-rise building with transfer story structure is performed by Push-over analysis with the finite element program MIDAS/Building.Study on the elastic-plastic action of structure under large earthquake ,find out occurrence law of plastic hinge and summarizes the collapse mechanism of structure. Analysis results show that: a high-rise building with transfer story under large earthquake, frame part is very difficult to appear a simple beam hinge, appear many beam-column mixed hinge.It is hard to achieve the seismic principle of strong-column-weak-beam. In practical projects, make columns strengthened through calculation and structural measures to ensure plastic hinge first appear in the beams;floors nearby transfer story ,especially shell walls near transfer beams are easy to get damaged under large earthquake,rebars in shell wall may get yield.Should strengthen the members at the end of the shell wall by structure measures.Also coupling wall-beam and short-limb shear-wall are weak and should suitably strengthened;in the plastic stage, level displacement and angle of shift near transfer story change suddenly.