Research On Seismic Assessment Theory And Methods Of Existing Brick Masonry Structure Based On The Theory Of Extension

Macroscopic damage shows that the casualties and economic losses caused by earthquake is mainly due to the collapse of housing construction and the damage of engineering facilities and equipment. Since the seismic capacity of brick masonry structures is more discrete, the brick masonry structures which contain potentially more unsafe factors in the existing structure during an earthquake should be everyone's concern. In the earthquake zones in China, there are a considerable number of constructions that do not consider earthquake-proof, although some consider the earthquake, due to historical reasons, others can not meet seismic requirements at present. In the process of seismic retrofit existing buildings, the first problem to be solved is the identification of earthquake resistance of existing buildings. The urgent problem is scientific and accurate evaluation of earthquake resistance of existing buildings.For a long time, the seismic identification of the structure has been using traditional seismic assessment methods. In this paper, according to the practical needs of the project, the existing brick masonry structure on the seismic rating of housing issues is studied by the integrated use of the basic theory of masonry structures, seismic theory, extenics theory, analytic hierarchy process, and proposed a set of theoretical and practical assessment methods. This paper conductes specifically the following aspects:Firstly, with the research on the existing seismic assessment, the existing brick masonry structures are standed seismic evaluation index system. Based on the consultation with a hundred experts, the analytic hierarchy process is used to determine the weight of the various indicators in the assessment; secondly, the extension is introducted in the seismic assessment of existing brick masonry structures in order to form the multi-level evaluation method based on the extenics theory, and establish extenics element model of seismic assessment about existing brick masonry structures. In the process of evaluation, through the analysis of existing seismic evaluation standards and engineering experience, etc.,this paper summarizes various influencing factors of seismic assessment about existing brick masonry structures, and establishes rating standards of each factor after dealing with dimensionless as a basis of extenics comprehensive evaluation; And then the steps of multi-level extenics evaluation about earthquake resistance of brick masonry structures are described; finally, the multi-level extenics evaluation methods are used to calculate many engineering cases, coming to the results of identification.Compared to the conclusions of the current evaluation methods, the conclusions of identification in this paper are further verified the correctness and feasibility; and this assessment method can distinguish within the same level, which is achieving continuous rating.