Seismic Analysis Of A Super High-rise Building Based On Performance Requirements

The seismic performance analysis and research are carried out on the background of super high rise tower structure of an offshore base.Firstly,this paper briefly introduces the engineering situation of the super high-rise tower structure,and selects the structural scheme based on the building scheme,engineering materials and load conditions.The shear wall structure and the steel frame center braced structure are selected to carry out the performance-based seismic comparative analysis,and the seismic performance of the two structures under frequent earthquake,fortification earthquake and rare earthquake is studied.With the help of YJK and Midas Building analysis software,the seismic performance of shear wall structure system and steel frame center braced structure system under small earthquake is analyzed by using mode decomposition response spectrum method.Using yjk analysis software to select 7 seismic waves that meet the requirements,the elastic time history analysis method is used to supplement the calculation of the above two structural systems.The results show that the two structures meet the requirements of elastic design and have good seismic performance under small earthquakes.Two kinds of analysis software are used to calculate the elastic and non yielding of the key parts of the structure system under moderate earthquake,and the seismic performance of the above two kinds of structure system under moderate earthquake is analyzed.The results show that the local shear wall at the bottom of the shear wall structure system is slightly damaged under the action of moderate earthquake,and the whole structure can meet the performance target under the action of earthquake;The steel frame center braced structure system shows that a small part of the brace is damaged,and most of the structure is in elastic state,which shows good seismic performance under the seismic fortification.Using Midas Building software to input three groups of seismic waves in accordance with statistical significance,select appropriate hysteretic model and constitutive relationship for structural components and materials,and carry out dynamic elastic-plastic time history analysis of shear wall structure system under strong earthquake.Based on the distribution of maximum story displacement angle and floor shear force,the weak floor and weak components are analyzed and judged,The hinge sequence and damage characteristics of frame structure and shear wall are analyzed.The results show that the stiffness of the structure is significantly reduced,the natural vibration period is prolonged,the damping ratio of the structure is increased,and the energy dissipation capacity of the structure is improved.Through the analysis results under the rare earthquake,it can be known that the energy dissipation components of shear wall structure can first play the role of consuming seismic energy,the common components and key components of the structure have no serious damage,and the whole structure can meet the requirements of collapse resistance under the rare earthquake.The static and dynamic elastic-plastic analysis methods are used to analyze the steel frame central support structure system.The ultimate bearing capacity of the structure is obtained by static elastic-plastic analysis.Based on the nonlinear displacement analysis results,whether the structure meets the predetermined performance objectives is analyzed and judged.At the same time,the dynamic elastic-plastic analysis is carried out,and the damage condition of the structure is discussed.It is found that under the rare earthquake,the support system,as the first line of anti-seismic defense,is seriously damaged,and the frame beam and frame column are slightly to moderately damaged.It shows that the steel frame central support structure system has good resistance to large earthquake under the rare earthquake.Based on the analysis of the calculation results,the corresponding optimization design measures are put forward for the steel frame central support structure system.Based on the above analysis,the seismic performance of shear wall structure and steel frame center braced structure is compared.Through the comparison of seismic performance under different levels of earthquake,it shows that the two structural systems can meet the pre-set seismic performance requirements.Through the comparison of the seismic performance of the two structural systems under the same level of earthquake,and the analysis and comparison of the comprehensive factors such as the micro and macro structural damage,seismic performance objectives,safety and applicability,economic durability and so on,it is considered that the steel frame central support structure system is more suitable for the super high-rise tower structure than the shear wall structure system,It has more advantages in seismic performance and comprehensive performance.