Research On Seismic Performance Of Super High-rise Structure Based On Elastic-plastic Analysis

Super high-rise building is a kind of high-rise building whose structural regularity exceeds the limit of the code to some extent.Every project has its unique complexity in the design process.In this paper,a 32 story business center office building with a total height of 138.9 m is taken as the research object.The seismic design method based on elastic-plastic analysis is adopted,and the relevant contents of seismic performance design are combined to solve the key problems in the actual over limit structural engineering.The commonly used elasto-plastic methods include static elasto-plastic analysis and dynamic elasto-plastic analysis.Because the structural model analyzed in this paper has the option of tower offset exceeding the limit,and there is a large gap between the mass center of the main building and the connecting layer of the podium,the dynamic elasto-plastic analysis method is selected.Through the dynamic elastoplastic analysis of the whole structure and the nonlinear deformation of each structural component and the elastoplastic damage state,the weak parts and weak components are found out,and targeted strengthening measures are put forward to ensure that the seismic performance of the structure can achieve the predetermined seismic performance goals.The main conclusions are as follows:(1)According to the current national code and the regulations of Shandong Province on seismic fortification of construction projects,the overrun options of high-rise buildings are determined,and four overruns of the structure,namely,torsion irregularity,floor discontinuity,size mutation and tower offset,are determined.According to the site conditions and seismic fortification intensity of the area,the appropriate seismic fortification performance targets are selected.(2)PKPM SATWE is used to analyze the response spectrum method of mode decomposition,and SATWE calculation results are taken as the basic design basis of the structure.Midas building is used to calculate the response spectrum as a supplement to SATWE.Through calculation and comparison,the whole structure and each member can meet the requirements of elastic design,and the indexes such as inter story displacement angle,floor shear force and rigid weight ratio can meet the requirements of the code.(3)The elastic time history analysis of the structure by yjk of yingjianke is used as the supplement of the response spectrum method.The error between the interlayer displacement angle and the base shear envelope value of the seven seismic waves and the calculation result of the response spectrum method is not more than 20%.The vertical seismic effect is considered in the stress analysis of the floor slab,which proves that the gallery slab can meet the performance requirements of shear resistance and non yield under rare earthquake.(4)Adopt Midas The dynamic elasto-plastic time history analysis of building and pkpmsauage under rare earthquake shows that the elasto-plastic state of the structure in the 9th to 12 th floors is relatively serious compared with other standard floors,because the 9th floor only has the structure layout of the standard floor of the main building,and the torsion of the podium itself affects the displacement of the main building so that the relative displacement angle of the adjacent floors is large;the hinge of the frame beam is common Some frame columns yield in bending,and some sections of shear wall in the bottom reinforcement area yield in bending,but the shear capacity is good without yielding,so local strengthening should be carried out according to the damage of components;the calculation results of the maximum inter story displacement angle and other calculation data prove that they can meet the requirements of rare earthquake,and the performance evaluation is made according to the relevant specifications,and the structure as a whole can achieve the seismic performance Target requirements for level C.(5)Yjk-ep is used to analyze the dynamic elastoplastic time history of the structure after adding viscous damper at the nodes with large displacement under rare earthquake.Compared with the original frame shear structure,the inter story displacement and floor shear force of the structure are reduced to a certain extent,and the hysteretic curve of the damper is relatively full,which shows that the damping technology should be used in the actual super limit high-rise structure It is feasible to use it.