Research On Application Of Large Commercial Complex Shock Absorption System

In recent years,in order to improve the utilization of urban land resources and meet people's needs for efficient,convenient and centralized living,the number of commercial complexes has shown a rapid growth trend.However,commercial complexes are usually irregular in structure,and has the characteristics of high floors,large spans,and many holes,and the ability to resist earthquakes is relatively weak.According to the current development trend,the future commercial complex will develop in the direction of more complex structural space and more diversified building functions,it also means that its seismic safety performance will face greater challenges.At present,it is a relatively efficient and economical seismic method to install energy-consuming shock absorption devices in structures.The shock-absorbing system composed of the energy-consuming shock absorption device and a frame structure can effectively improve the seismic performance of the structure,and how to choose the most suitable energy-consuming device for the commercial complex is particularly important.Therefore,this paper studies the application of different types of energy-consuming shock absorption devices in commercial complex,taking a large commercial complex in a practical project as the research object,the Buckling-Restraint Brace(BRB),Shear Damper(SD)and Viscous Fluid Damper(VFD)are arranged at the same position of the structure,the main research contents are as follows:1.In order to improve the torsional deformation and the large displacement of the structure,firstly,a BRB scheme with better damping effect is designed,and the elastic and elastc-plastic time history analysis of the uncontrolled structure and the BRB structure is made.The results show that under frequent earthquakes,BRB effectively reduces the torsional effect of the structure and the story drift by providing additional stiffness,but at the same time enlarges the story shear force and the top acceleration response of the structure;under rare earthquakes,BRB significantly improved the dynamic response parameters of the structure.2.In this structure,the shock absorption scheme of SD is adopted.Based on this scheme,the torsional deformation and story displacement of the structure can be effectively reduced,and study the influence of the support stiffness and yield displacement of SD on its damping effect.Firstly,elastic time-history analysis is conducted on the SD structure in the plane.It is found that the larger support stiffness and the smaller the yield displacement,the better the damping effect of SD would be.Then,these two parameters are studied in the structure,and a number of dynamic response parameters of SD structure under small,medium and large earthquakes,it is found that when the ratio of support stiffness to the elastic stiffness of SD is controlled at 1 ? 1.5,the SD scheme can achieve a good balance between the shock absorption effect and the economy;it also researches the SD under the support stiffness ratio of 1,and different yield displacements,it is suggested to control the yield displacement within 1 ? 1.5mm based on various factors;all support sections in the structure are kept consistent,and the effect of yield displacement on SD is studied,it is found that when the yield displacement within 1? 2mm,SD has a higher damping efficiency.3.In this structure,the VFD damping scheme is adopted.By changing the parameters of VFD,different additional damping ratios are obtained,and the additional damping ratios of 3% and 4% provided by VFD are brought into the structure for calculation,the control effect of the displacement ratio and lateral displacement of this structure is relatively limited.4.Comparing the damping effect of BRB and SD with the same lateral stiffness:the damping effect of BRB and SD are basically the same under frequent earthquakes,but the BRB is more effective under rare earthquakes;in the BRB structure,the BRB amplifies the column axial forces of the substructure;when SD is arranged in the form of support,it has a great influence on the bending moment of the beam and column of the sub-structure.Finally,the economy of the two schemes is compared,and it is found that the cost of BRB scheme is lower,saving about 20% of the cost compared to the SD scheme.