| The reconstruction technology of supporting beam drawing column can flexibly change the architectural plan layout,expand the space and expand the column distance,and it has been widely used in the structural transformation project of our country.In the process of column removal reconstruction,different column removal schemes will not only directly affect the seismic performance of the structure,but also determine the reinforcement scheme and reconstruction cost of the structure.However,at present,domestic and foreign scholars have little research on the seismic performance of the whole structure with column removal schemes.Therefore,in this paper,a finite element model is established with an existing RC high-rise structure reconstruction project as an example by numerical simulation,and based on IDA method,the influence of the existing RC high-rise structure on the seismic performance of the beam and column pulling is studied.The main research achievements are:(1)IDA method was used to analyze the frame-shear structure before and after the removal of columns.Through comparative analysis,it was found that the removal of a certain number of columns in the podium of the frame-shear structure would weaken the seismic performance of the whole structure to a certain extent.However,in view of the low column removal rate of 3.74% and the intact shear wall subjected to horizontal earthquake,the maximum weakening range was only 3.48%,within 5%,which means the structure still has strong seismic capacity after pulling out the column.(2)A simplified frame model is used as the research object to analyze the influence of the number of pull-out columns,the plane position of pull-out columns,the elevation position of pull-out columns and the number of pull-out columns on the seismic performance of the structure.The results show that the higher the rate of column removal,the greater the degree of seismic performance weakening and the faster the rate of seismic performance weakening.The least square method is used to get the fitting curve of seismic performance weakening coefficient and column removal rate.When the column removal rate is the same,the removal of side column and corner column will weaken the seismic performance of the structure more than the removal of middle column.When the extraction rate of the column is not more than 16%,the deterioration coefficient of the side column Bc is 0.85,and the deterioration coefficient of the corner column Jc is 0.75.The removal of the structural column will lead to the transfer of the weak layer to the removal column layer,and the removal of the side column and corner column will further accelerate the transfer and development of the weak layer.The higher the number of floors,the less the seismic performance of the structure is weakened.The law of the removal of single-layer columns still applies to the removal of multi-layer columns,and when the removal rate of columns does not exceed 20%,the seismic performance weakening effect of the removal of multi-layer columns on the structure can be regarded as the linear superposition multiplication of the seismic performance weakening effect of the removal of single-layer columns on the structure,and then multiplied by the safety factor of 0.75.(3)The frame-shear structure after column extraction is taken as the research object for reinforcement research.The corresponding reinforcement scheme is formulated according to the reinforcement requirements and the national norms and construction needs.The security of the reinforcement scheme is proved by theoretical checking calculation,and the effectiveness of the reinforcement scheme is proved by numerical simulation.The results show that a series of reinforcement schemes formulated in this chapter are safe and effective,and meet the requirements of national standards. |
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