Study On The Fuzzy Comprehensive Evaluation Method For Safety Of Masonry Structure Based On Grey Clustering Theory

In view of the existing masonry structure safety evaluation methods, there are many problems such as qualitative evaluation method is difficult to reflect differences in the same security level, and quantitative evaluation method is difficult to apply. Aiming at these problems, this paper carries out the study on the quantitative evaluation method of safety of masonry structure.According to the basic idea of analytic hierarchy process, combined with the stress characteristics of masonry structure under the condition of normal using load, establish a hierarchy evaluation model of three levels, in which a masonry structure is divided into sub-unit, sub-point and checkpoint. This evaluation model partition the masonry structure into two sub-units of foundation and upper structure, divide the sub-unit into several sub-points contain subsoil, infrastructure, wall-column, beam, floor and parapet, and the sub-points into few checkpoints conclude carrying capacity, deformation, structure, crack and unity. Based on the hierarchy evaluation model, the fuzzy mathematics theory and grey clustering theory are introduced into the safety evaluation of masonry structure, and the judgment matrix is constructed by using the e0/5～e8/5 scale method, and fuzzy weight vector is calculated by using generalized eigenvalue method. On the foundation of measured data of structure, clustering coefficient matrix is counted by constructing a whitened function, which is used as comprehensive evaluation matrix. Put forward a three grade fuzzy comprehensive evaluation method on the safety of masonry structure, and verify the application and feasibility through engineering examples.The results show that the fuzzy comprehensive evaluation method for safety of masonry structure based on the grey clustering theory, which combines analytical hierarchy, grey theory and fuzzy mathematics theory, is able to evaluate the overall security level of the masonry structure quantitatively, and fully reflect the influence of various factors on the safety of the structure, not only is clear in concept, and easy to operate.