A Study On Safety Appraisal And Evaluation Method Of The Building Near Deep Foundation Pit

The building structure is in service,people are most concerned about is the security of the structure itself.The safety of building structure is closely related with the architectural design and the forming environment as well as the correct operating and maintenance.At the present stage of urban construction,there will often have existing buildings near the foundation pit and the building is inevitably affected by the adjacent construction.Therefore,it is necessary to study the safety appraisal and evaluation methods of such buildings to ensure the safety of the building.In this paper,the masonry structure affected by the construction of the foundation pit is the main research object.The purpose of this research is to study the safety of the structure itself,by using the in-situ inspection,data analysis and modeling checking.To carry out a comprehensive assessment method and put forward the measures and suggestions for the building's security risks.Based on the in-depth study of safety appraisal theory and on-site testing technology of the existing structure,the paper has applied the following aspects to study the content of the research.1)First of all,the procedure of on-site testing is introduced.In terms of improving the accuracy of in-situ inspection,from the statistical point of view,the sample capacity was optimized and improved.At the same time,a kind of verification method is given for the abnormal inspection data.According to the characteristics of the masonry structure,the content of the in-situ inspection is studied.2)Secondly,on the basis of the existing research,the theoretical basis of the assessment of existing structural safety is studied,the basic principles of structural mechanics analysis and checking are discussed,The standard value of the load and the method of determining the standard value of the material strength are put forward,and the safety appraisal should be combined with the seismic appraisal.The method of the dividing influence area of the foundation pit construction is introduced,and the relevant investigation contents of the adjacent building safety appraisal are expounded.3)According to the hierarchical division and working steps of the safety appraisal of civil buildings,the comprehensive evaluation method of the existing masonry structure is studied,and the evaluation methods of the components,subunits and appraisal units are studied respectively.Aiming at the shortages of the existing evaluation standard of foundation subunits,the partial evaluation indexes are quantified,and the efficiency of the appraisal work is improved.4)Finally,with the specific engineering example to apply the previous research results,through the detailed in-situ inspection,obtains the performance information such as the arrangement of the building,the configuration of the structure,the distribution of the cracks,the status of the settlement deformation and the strength of the material.On the basis of measured information,the overall bearing capacity of the structure is analyzed by using the JDJG module in PKPM structure analysis software.Based on the analysis data and other inspection results,the overall safety of the building is evaluated,and the safety level of the building is obtained.According to the results of the assessment,the measures and suggestions are put forward for the safety issues existing in the building.