| With the rapid development of society,the pace of urban construction is accelerating,result in shortage of urban land resources.Building gradually increased in height and function is more and more complex,with the emergence of the high-rise building conversion layer meets the bottom large space and the upper residential office use demand.More and more construction projects exceed the standard requirements in terms of height and regulation,under the earthquake,the reaction is strong,the internal force deformation is large,the performance index is not easy to control,often exists weak spot,in order to improve the reliability of this kind of structure design,should carry out ultra limit Project review and structure analysis in strict accordance with the norm.The frame-barrel structure with conversion layer is widely used to satisfy people’s demand for high-rise buildings and different functions as much as possible,the lower floor as shopping malls,hotels and cultural and entertainment facilities,the upper floor as office and residential,to meet the needs of different vertical function simultaneously.At present,the transformation layer is in various forms,increasingly in-depth research,the different conversion layer forms and position affect the structure overall,how to reasonably set the conversion layer become an important research direction of the ultra-limit high-rise structure.In this paper,the study of the frame-tube ultra-limit high-rise structure with a conversion layer is as follows:1.According to the engineering example,a ultra-limit frame tube structure in the high seismic intensity area of Yinchuan as the research object,the finite element analysis design software SATWE and ANSYS are used to establish the original scheme with beam-type conversion layer frame-barrel structure model.Changing the transformation layer form,replacing the girder conversion layer with the truss conversion layer,the other floors remain unchanged,and the truss frame-tube structure model is rebuilt.Combining the specification analysis and adjusting two kinds of frame-barrel structure model to satisfy the specification requirement.2.Modal analysis,response spectrum analysis and elastic time history analysis of two frame tube structures with SATWE,comparing the periodic ratio,vibration mode,interlayer shear force,floor bending moment,layer displacement and the difference of displacement angles between two kinds of frame tube structures,the characteristics of frame tube structures of two different kinds of conversion layers are obtained.Using ANSYS to analyze the modal analysis and time-history analysis of twoframe-barrel structures,comparing the results of complementary verification SATWE software.The results show that the truss-type conversion layer structure has better resistance to lateral stiffness and torsion stiffness,and reduces lateral displacements of the structure of the whole;the truss-type conversion structure has a smaller stiffness mutation near the transformation layer than the Truss type conversion structure and it is more advantageous to the aseismic structure.3.On the basis of the comparison of the structure form of the conversion layer,the structure of the truss-type conversion layer with better conversion effect is selected,replacing three times conversion position,modal analysis and response spectrum analysis through SATWE respectively,comparing the changes of shear force,bottom bending moment,layer displacement and the change of displacement angles between the floors,and the rule of the change of transition layer with the position of the ultra-limit structure in high-order conversion is obtained: With the increase of the height of the conversion layer,the translational cycle change is smaller,but the torsion cycle is obviously increased,and the torsion effect of the ultra-limiting structure is more obvious.The floor bending moments of the transition layer and the lower floors are increasing.There are obvious mutations in the interlayer displacements and the displacement angles of the transition layer,and the amplitude of the ultra-limiting structure is more evident in the transition layer stiffness mutation,and the more disadvantageous to the aseismic structure. |
