Research On Influence Of High-rise Concrete Frame Shear Structure Characteristics With BRB Seismic Reduction And Reinforcement

In high-rise frame-shear wall structure,the arrangement of buckling-restrained braces is an effective means of energy dissipation and shock absorption.In the study of the frame-shear structure arrangement for buckling-restrained braces,only the placement of BRB on the story with large deformations is very helpful for structural shock absorption,but it is not the best layout for increasing the bearing capacity of the bottom member and the overall safety reserve of the structure.In this paper,the design method of the BRB bearing layer shear ratio is selected to analyze the energy dissipation and shock absorption characteristics of the buckling-restrained braces at different positions of the high-rise frame-shear structure in order to summarize a reasonable high-rise frame-shear wall The lower part of the structure is provided with buckling-restrained braces schemes,and the shear ratio parameter with the best energy dissipation and shock absorption effect is selected to provide a certain application reference for the shock absorption of this type of engineering structure.(1)Built a 15-layer frame shear wall structure(Model I),a 20-layer frame shear wall structure(Model II)and a structure that reduces the thickness of the shear wall by 20% on the basis of Model I(Model III).The shock absorption effect of the BRB at different locations of the structure was studied.The layout 1of the bottom floor of the structure,the layout 2 of the lower floor and the layout 3 of the middle floor are used to arrange buckling-restrained braces.The energy dissipation and shock absorption effects of the three layout schemes are analyzed.The comparative analysis of the structural dynamic response,BRB hysteretic energy dissipation and shear wall stress under the three layout schemes shows that the high-rise frame shear wall structure with buckling-restrained braces at the lower part has a certain damping effect and is rarely encountered by earthquakes The damping effect under the action is better.Layout 1 contributes less to the structural shock absorption and energy consumption than the other two layout schemes.Layout 2 has a slightly better energy consumption and shock absorption effect than layout 3.Layout 2 can effectively reduce the tensile and compressive stress of the bottom shear wall.Therefore,the arrangement of buckling-restrained braces at the lower part of the structure can be used as the energy dissipation and vibration reduction scheme of the high-rise frame-shear structure.(2)The effect of BRB under different shear ratios on the energy dissipation and damping characteristics of the structure under the same layout scheme is studied.Through the comparative analysis of the interlayer displacement of structures withdifferent shear ratios,the proportion of BRB energy dissipation and the influence on the stress of the frame beam and column,the results show that different shear ratios have different effects on the energy dissipation and shock absorption of the structure.The energy dissipation and shock absorption effect of the structure is not good.The comparative analysis of the dynamic response of the BRB structure with four shear ratios(0.3,0.4,0.5,0.6)shows that the design shear ratio has an increasing function trend with the overall seismic performance of the structure,that is,when the design shear ratio is 0.6,the structure The energy dissipation and shock absorption capacity is the strongest,and the displacement angle between the structural layers is the smallest.In the local position of the BRB,the shearing stress and axial tensile and compressive stress of the frame beam and column are the best.(3)The PERFORM-3D structural analysis software was used to perform the static elastoplastic analysis of the BRB structure and the original structure and the dynamic elastoplastic analysis under the bidirectional earthquake.The placement of BRB in the frame-shear wall structure significantly improves the lateral resistance of the structure.The slope of the base shear-apex displacement curve of the structure increases,the structural performance point decrease,and it can delay the development process of the frame beam and column plastic hinge.Comparing the structural responses under bidirectional and unidirectional earthquakes,the deformation of bidirectional ground motion structures is greater than that of unidirectional earthquakes.(4)The shock absorption effect of the scheme was verified in combination with the actual project.The example analysis shows that the BRB reinforcement scheme can increase the overall seismic performance of the structure and reduce the overall displacement of the structure.In the case of frequent earthquakes,the X-direction structural interlayer displacement angle is reduced from 1/758 to 1/986,and the Y direction is reduced from 1/781 to 1/1025,effectively solving the problem of insufficient seismic performance of the original structure.And fully enhance the energy consumption of the structure.