Research On The Comprehensive Assessment Method Of The Safety Of The Existing Building Structures

Existing building structure is completed, the structure itself will continue to be influenced by the natural environment and human activities, and coupled with the passage of time,the structure itself will be constant aging,and the original performance and the performance to fight against the disaster will be gradually degenerate. when the structural safety tends to limit state,it will be a direct threat to the structural safety of existing structures. In order to continue to play its due role, we need to carry out the safety assessments, for the maintenance, reinforcement and transformation to provide the basis. And the current our country existing building structural safety assessment method needs to be further study. Therefore, in order to improve the accuracy and scientific of the existing building structural safety assessment conclusion, through the analysis of the summary, expansion of existing building structural safety comprehensive evaluation method research, main research contents are as follows:(1)Research on the basic theory of safety assessment of the existing building structure. Combined with the current research of the existing building structure safety assessment and the literature data, arranging the structural reliability theory, studying of the basic theory of safety assessment of building structure.Through the analysis of the theory, combined with the current situation of domestic and international relevant research, analysising the problems existing in the current existing building structure safety assessment method.(2)Research on the comprehensive evaluation index system of the safety of the existing building structure. Through the analysis of safety appraisal case, combined withrelated standards and data,analysising(wood structure, masonry structure, concrete structure, steel structure building structure of the four structure) safety influencing factors and assessment content, combined with the force transfer path in the structure system is used to divide the component importance level, finally constructs the existing building structure safety assessment index system and using Lagrange conditional extremum of combination weighting method to calculation the weight.(3)Research on the comprehensive assessment model of the safety of the existing building structure. Through the qualitative and quantitative assessment of their characteristics and applicability of the inductive analysis, combined with the establishment of the evaluation index system, considering the selection of matter element extension method to build the model of the comprehensive assessment of structural safety, respectively, the index system of quantitative, correlation function establishment, assessment standards and process content were analyzed one by one.(4)Case study of comprehensive assessment model for safety of building structures.To Beijing for a financial business district show center security appraisal project as example, based on the existing building structure safety assessment method to Beijing for a financial business district show center project of safety assessment, finally give a quantitative evaluation of the results, the feasibility of model validation and applicability, for subsequent software development lay the foundation.(5)Research and establishment of decision aided software for comprehensive assessment of safety of building structures. Considering existing in the comprehensive evaluation method of building structure safety model calculation is too complicated,and hand calculation is too complicated, and considering the ability to achieve a reasonable,fast and effective safety assessment, devoted to the study of the preparation of the corresponding auxiliary calculation software. The software is developed based on the.Net platform, which mainly includes four parts: wood structure, masonry structure,concrete structure and steel structure..Finally, the validity and feasibility of the software is demonstrated by an example.