Mechanical Research Base On Column Removeing And Beam Supporting Process Of High-Tise Frame Structure

As China's construction industry enters the stage of both new construction and reinforcement,strengthening and reconstruction technology is increasingly valued by scholars,and the comprehensive special engineering technology such as "column removeing and beam supporteing",which can effectively improve the use space of buildings,has important research value.The research of this paper is based on the column removeing and beam supporteing project of a high-rise reinforced concrete frame structure.This paper introduces the strengthening and reconstruction method used in this project,evaluates the strengthening and reconstruction effect.and the whole process simulation analysis of the construction process of the column removeing and beam supporteing was carried out using finite element software.And then makes a comparative analysis of the change of the structure's progressive collapse resistance and robustness after the strengthening and reconstruction of different schemes(inclined brace strengthenting method and structure member strengthenting with RC).The main contents of this paper include:(1)A detailed introduction to the column removeing and beam supporteing project involved in the article.Before the construction of the column removeing project,the structure was strengthened with the inclined brace on the upper part of the column to be removed.At the same time,the two middle columns connected to the bottom of the bracing were strengthened with externally bonded steel.Due to the establishment of a complete monitoring system before the column is pulled,the reinforcement project is completed in an orderly manner under controllable conditions.Through the monitoring system,the displacement of the key parts of the structure and the strain of the important components during the processing are obtained,and the whole process of the construction of the column is realized.The monitoring results show that the reconstruction method can control the deflection of beam beam at the top of the column and lateral displacement of floor well,and ensure that the new and old members have coordination deformation and work together.The house does not have uneven settlement and the reconstruction effect is good.It provides a simple and feasible method for monitoring the construction process of such strengthening projects.way.(2)The author used the OpenSEES finite element software to establish athree-dimensional model of the structure through the monitoring system to obtain various data during the construction process,and the whole process simulation of the construction process of drilling columns was carried out.Innovatively The process of drilling and cutting column is simulated by using the common node elements and remove element commands in the OpenSEES,and the equivalent reaction method was used to replace the support system,the simulated values of the whole process of vertical displacement curve at the top point of the removed columns are in good agreement with the measured values,indicating that this method can better simulate the construction monitoring process of this type of projec.It can provide a method for the simulation of the construction process of such projects to achieve the purpose of reducing safety risks and improving the effect of reinforcement and transformation..(3)The OpenSEES software was further used to design the “enlarged section method” for this project.In order to study the changes of the progressive collapse resistance of the structure after the modified bracing method and the enlarged section method and the original structure,the original structure and the structure strengthened by the two different methods were calculated and analyzed by the nonlinear dynamic demolition method.The calculation results are compared with the progressive collapse criterion at home and abroad.It can be seen that the original structure and the structure strengthened by the two different methods have sufficient resistance to progressive collapse.(4)Using OpenSEES software,the robustness of the original structure and the structure reconstructed by different methods is quantitatively analyzed.The quantitative analysis method combines the importance coefficient of component and the vulnerability coefficient of component.The calculation results show that the two types of column reconstruction schemes will weaken the robustness of the building structure and the degree of weakening is similar.Furthermore,the reasons why the robustness of the structure is weakened are analyzed,and further strengthening suggestions are proposed.