Research Of The Evaluation Methods After The Earthquake In Chinese Ancient Buildings Based On The Fuzzy Mathematics Theory

Chinese ancient structures which are regarded as the representative of eastern architecture have riched in historical value, cultural value and scientific value, and it haven’t been replaced. The existing ancient structures under the influence of various complicated factors have been a decline in its seismic performance. So that it is easy that they are rejected to damage. Evaluation of the extent of damage has become particularly important. Because only accurate assessment of earthquake can provide a basis for rational and economical maintenance. Especially after the wenchuan earthquake and lusan earthquake, a large number of the ancient buildings under different damages need to be evaluated. Therefore, studying of the method for evaluating the ancient buildings after the earthquake has a great significance.based on the fuzzy mathematics theory, evaluation methods of wood and masonry ancient buildings after the earthquake were discussed. The main research contents and results are as follows:(1) The ancient building is divided into the foundationsoil, foundation and upper structure of three relatively independent systems, three parts of multiple evaluation index is selected as evaluation factors and the ancient buildings of the earthquake damage level, evaluation level and service level were corresponding divided. Combining with fuzzy mathematics theory, the fuzzy general evaluation method of evaluating ancient buildings after the earthquake has been purchased.(2) This paper has proposed the comprehensive evaluation method of the ancient timber buildings after the earthquake based on fuzzy mathematics, frist of all, the characteristics of ancient timber structure damage caused by the earthquake are analyzed. Combining with the main mechanical properties of wood, eleven index as evaluation factors which influence the appraising of the earthquake can be selected. Secondly, the evaluation of grade is described by using membership function. Thirdly, the relative proportion is determined by using the improved analytic hierarchy process (AHP) and analogy method. Finally, according to the principle of fuzzy recognition, we can get the result of whole structure’s fuzzy evaluation.Establish the huangdi temple which is in qingcheng mountain finite element model for nonlinear analysis,and combining with the actual earthquake damage. The results show that the fuzzy mathematics comprehensive evaluation method has applicable.Then, it is evaluated after the quake that using fuzzy mathematics comprehensive evaluation method and probability evaluation method. The result proved that With probability theory, results of the two methods are continuous and accurate, avoiding interruption. However, because the index assumption isn’t modified and the selection of indicators are not comprehensive, the result of probability evaluation method has deviation. On the contrary,The result demonstrates that the fuzzy comprehensive evaluation method has relatively accurate and distinct, so that it can be applied to practical engineering more easily. (3) The characteristics of ancient masonry structural damage caused by the earthquake is analyzed, combining with the main mechanical properties of masonry structures. This paper has proposed the fuzzy comprehensive evaluation method of the ancient masonry structure after the earthquake which is similar to that of the ancient wood structure. The Chen’s house finite element model is established for linear analysis of the structure,and combining with the actual earthquake damage. The results show that the fuzzy mathematics comprehensive evaluation method of ancient masonry stucture has applicable.By comparing with the evaluation results of the fuzzy mathematics comprehensive evaluation method and those of set pair analysis evaluation method, we can find that the accuracy of the fuzzy comprehensive evaluation method of ancient masonry structure is higher,and it has more advantages in the practical applications.