Analysis Of Seismic Reduction Scheme And Identification Of Seismic Reduction Efficiency In High-rise Bulding Linked With Connective Structure

The research object of this paper is a double-tower high-rise rigid-connected structure located in the area of 8 degrees(0.2g).It integrates the characteristics of complex connection,height overrun,irregular plane,energy dissipation.The structure is formed by a low tower with a height of 138.15 m and a high tower with a height of195.15 m on the 26 th to 29 th floors through 3 floors and 4 floors rigidly connected,wherein the core tower of the low tower is offset.It consists of 168 sets of viscous dampers and 136 sets of buckling restraint braces.Around this object,the main issues and content of the research are based on four aspects.First,the interaction mechanism of the two towers along the two main axes of the structure and the effect of this effect on the internal forces of the connecting members.The scheme and performance control of the connecting body are the key links in the design of the structure.The interaction mechanism between the two towers is a key feature of this link.In this paper,the vibration mode decomposition response spectrum method is used,based on the results of the two analysis software,and the interaction mechanism is revealed by screening the main indicators of the structure.And a simple structural model is established,combining the internal forces of the components,the contribution of each component of the connector to the interaction is expounded.Second,the correlation between the response of the energy dissipation device and the displacement of the high-rise structure characterized by bending and shearing.Analyzing the correlation between the two is helpful to efficiently arrange energy dissipation device and understand the analysis results of strctural with energy dissipation device.Based on the two types of devices and three types of layout used in the research object of this paper,the deformation of the unit is decomposed from the bending-shear type deformation.Through the establishment of calculation examples,the correctness of deformation decomposition is verified,and the correlation between energy dissipation device response and structural displacement is established.Third,the research object’s shock absorption efficiency under the frequent and rare levels.Under the frequent encounter level,the responses of non-shock-absorbing structures and shock-absorbing structures under 7 sets of ground motions are calculated respectively,and compared with the macro-indicators and detailed characteristics.At the same time,the two methods for calculating the additional damping ratio are compared and analyzed,and the similarities and differences in energy dissipation of different energy dissipation arrangements are discussed;Under the rare level,the responses of the nonshock-absorbing structure and the shock-absorbing structure under three groups of ground motions are calculated respectively.The effects of shock absorption are analyzed from the aspects of macro indicators,energy dissipation mechanism and structural performance status.The response characteristics of the energy dissipator under different arrangements are compared.Fourth,the performance state of the shock-absorbing structure under rare conditions.Based on the analysis results of the nonlinear dynamic response of the shock-absorbing structure,the performance status of each member in the shock-absorbing structure is analyzed to determine whether the structure is safe under the rare level and whether the expected reasonable plastic distribution mechanism is formed.By studying the above four issues and completing the corresponding analysis,the main conclusions obtained in this article are:1)After the engineer’s system design,the coupling between the various vibration modes of Tower B is still good,and the structural indicators under the standard level meet the specification limits.The interaction between the two towers can be understood as a "help mechanism".This mechanism is represented by the overall torsion of the structure in the X direction,and in the Y direction as a force transmission method similar to the portal frame.Under this mechanism,the stress of the connecting body is similar to that of a small-span-height ratio beam that bears large shear forces,large bending moments,and axial forces that cannot be ignored.Among them,the webs of the main truss provide shear resistance,and the upper and lower chords of the main truss,in-plane diagonal braces,and the bottom and top floors of the connecting body provide bending resistance.Combined with the design results,the cross-sectional size of the web rod is large and the force is large.The section of the main truss is controlled by the internal force under the Y-direction earthquake.2)After removing the harmless deformation and the minor deformation,the correlation between the shock absorber response and the structural displacement in each arrangement is obtained.The maximum damping force and maximum displacement of VFD in Form A are related to the shear angle,and the maximum displacement of BRB in Form B is related to the shear angle.Regarding Form C,the concept of sub-cell bending angle is proposed to prove that the maximum damping force and maximum displacement of VFD are related to the sub-cell bending deformation.3)Under the frequent encounter level,the reduction of the displacement angle between the floors of Tower B can basically reach about 10%,and the additional damping ratios calculated by the energy ratio method and the standard method are 1% and 1.4%,respectively,and the wall-type viscous damper The additional energy consumption accounts for about 55% of the total additional energy consumption,and the cantilever damper truss accounts for about 45% of the total additional energy consumption.4)Under the uncommon level,the reduction of the displacement angle between the floors of Tower B can basically reach about 5%.Inelastic energy consumption accounts for 51% of the total energy consumption,and inelastic energy consumption accounts for45% of the total energy consumption.The additional energy consumption of the wall viscous damper accounts for about 60% of the total additional energy consumption,the additional energy consumption of the cantilever damper truss accounts for about 30% of the total energy consumption,and the additional energy consumption of the buckling restraint support accounts for 10% of the total energy consumption.5)Under rare circumstances,the plastic development of the shock-absorbing structure is mainly concentrated on the coupling beam and the frame beam,and the coupling beam has a greater degree of plasticity.The shear wall only yields very little at the bottom layer,and few frame columns yield.A small number of webs in the main truss of the connecting body yielded.When the main direction of ground motion acts along the Y direction,the performance of the structure is slightly better than that along the X direction.The yield mechanism of Tower B at the rare level meets expectations and the structure is safe.