| Since the reform and opening up,China’s construction industry has developed at a high speed,but along with the passage of time,a large part of existing buildings cannot meet the requirements of use due to the change of use function and other reasons,and must be renovated to ensure that the buildings continue to be used normally.In order to serve the overall situation of urban renewal,compared with large-scale demolition and reconstruction,most of the original buildings are retained and columns and beams are extracted where large spaces are needed.Therefore,this technology is increasingly used in housing renovation projects.In this paper,the safety of a column and beam extraction project of an existing building in Hefei City is demonstrated by using a combination of MIDAS overall model analysis,ABAQUS finite element isolation model analysis,and on-site real-time monitoring,and the following research results are obtained:(1)The background and significance of structural strengthening and renovation of existing buildings are comprehensively described,and the application and development of extracted column joist technology in this field are explored;and the concept,design ideas and common methods of extracted column joist technology are introduced through a literature review of existing relevant studies at home and abroad;then the combined beam+ steel diagonal bracing system is proposed as the solution for this extracted column joist project,which is considered to be ingenious and simple in force transmission,with less bars and nodes,less construction difficulty,and less impact on the overall index of this frame structure system,which is difficult to be achieved by other bracing methods;(2)Combined with the extracted column and joist project of an existing building in Hefei,the finite element model of the extracted column and joist project was established by using MIDAS finite element software,and the overall calculation of the model was carried out by using a partial safety equivalent section for the combined beam,and the overall calculation results of the project were obtained,and the stress distribution and deformation were basically within the code requirements.The results of the additional calculations on the overall seismic performance of the structure were all within the requirements of the code,and the reinforced structure was considered to meet the seismic level of "no damage in small earthquakes and no collapse in large earthquakes";(3)The ABAQUS finite element software was used to analyze the isolated body model of the extracted column joist project,and the key steps of the modeling,such as the material parameter properties and the division of the mesh,were explained;the stress and displacement results obtained from the isolated body model were compared with the relevant codes,and the results were within the code requirements;(4)The dynamic monitoring records during the construction process and the real-time monitoring data after the completion of the construction of the extracted column joist project were compiled.After five times of dynamic monitoring data records,the displacement data finally gradually converged and reached a stable state;at the same time,the real-time monitoring displacement curves were collected for more than half a year after the completion of the construction,and by reading the displacement curve amplitude changes at the relevant points,it was found that the curves on the basis of the original displacement almost no change,indicating that the structure has been in the working condition of normal use;(5)Comparing the simulation results of ABAQUS software with the stress and displacement values obtained from the overall calculation of MIDAS and the real-time monitoring data,it is concluded that the reinforcement and reconstruction plan of the extracted column joist is reasonable and safe,and can be used as a reference for similar projects.Figure [72] table [17] reference [56]... |
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