Analysis Of Seismic Performance Design Of Out-of-code High-rise Building

The high-rise buildings are constructed as an efficient approache to alleviate the intensified shortage of urban land,mprove the urban imag,and boost the economic development.Due to the requirements from architectural appearance,function and economical efficiency,super high-rise buildings with horizontal and vertical irregular structural arrangments are increasingly adopted.One of the major issues of their structrual design is the seismic performance design.Combined with the design of the No.2 Tower of Nanchang Zhengsheng Taigu Commercial Plaza,several structural schemes are compared,and the seismic performance is analyzed and optimized.The major work and conclusions are as follows.1.Structural cheme selection.According to the design code,it is determined that the structure is a high-rise building exceeding the code's B-level height requirement.The frame core-tube system and frame-shear wall system are taken as preliminary structural schemes.The corresponding FEM models are created respectively considering a range of factors as structural height,global stability,shear wall arrangment,and connection detail,and the analyzed results including natural frequencies,rigidity weight ratio,shear weight ratio,and the interlayer displacement angle are compared.Finally the frame-shear wall system is selected as the determined structural scheme,and the target C is selected as the seismic design performance target.2.Structural seismic effect analysis under frequent earthquakes.Using YJK structural analysis software,structural seismic effect under frequent earthquakes is calculated by mode-superposition response spectrum method and elastic time history analysis.By examining structural displacement and internal force,the structure is evaluated and optimized.After optimization,The results showe that the structure as a whole is in elastic state,the maximum interlayer displacement angle is 1/1000,and the seismic performance of the structure accords with the requirements of “no damage in frequent earthquake”.3.Elastic-plastic analysis for the structure under rare earthquakes.The softwares of PUSH&EPDA and SAUSAGE are applied to conduct static elastic-plastic analysis and dynamic elastic-plastic time history analysis.Such structural effects as base shear,maximum interlayer displacement angle,and vertix displacement are checked,and the seismic damages of key components are evaluated.The overall structure is analyzed andthe damage degree of the key components is evaluated.Results show that the maximum interlayer displacement angle of the tower is 1/154,and the maximum vertix displacement is 0.765 m.The plastic deformation,structure failure position and failure sequence agree with the design expection,and the overall structure meets the requirements of “no collapsing under rare earthquake”.