Application Research On Storey-adding Reconstruction Of Frame Structure

With the increasing tension of land resources,the storey-adding project is becoming more and more common.The lateral stiffness of the frame structure can be improved by increasing the shear wall and the buckling restrained brace in terms of earthquake resistance.Compared with the shear wall,the buckling restrained brace has the advantages of light weight,low cost,convenient construction and flexible arrangement.It is widely used in increased layer transformation and reinforcement engineering.In this paper,the Midas Gen finite element software was used to analyze the dynamic characteristics of the frame and the frame-shear wall increased layer structure.Also,the deformation characteristics and stress characteristics of the two types of building under the influence of earthquake was compared.The results show that the vibration mode and deformation characteristics of the storey-adding structure with the shear wall are more reasonable than those of the frame structure.On the basis of the finite element analysis,the single-inclined,V-shaped and inverted V-shaped buckling restrained braces are arranged on the adding-storey structure.The seismic response of adding-storey frame structure with the three buckling restrained brace was analyzed by using the mode decomposition response spectrum method and the time history analysis method under frequent and rare earthquake.The results show that,(1)Under the action of earthquake,the translational component of the first two main modes of the adding-storey frame structure with additional buckling restrained brace is increased;The inter laminar shear force increases with the increase of the overall stiffness;(2)The displacement angle of the floor with the buckling restrained braces is significantly reduced,and the other floors are slightly increased,but the overall stiffness is improved;(3)Under the action of rare earthquakes,the buckling restrained braces have the effect of dissipating seismic energy,which is more favorable for the structure seismic response(4)Different forms of buckling restrained brace have great influence on effect of the shock absorption and the damping effect of the inverted V-shaped support is the most significant.And according to the inverted V-shaped support scheme,the Y-direction support position is adjusted to obtain the influence of the support position on the shock absorption.Finally,based on the PKPM modeling of frame-shear wall and buckling restrained brace adding-story scheme,the method of strengthening the cross section is used to reinforce the existing structural beam and column members.For the components with axial compression ratio beyond a small range,the carbon fiber cloth is used for reinforcement,and the relevant measures in the structure are given.