Comprehensive Evaluation Of Fuzzy Reliability On Reinforced Concrete Structure

Nowadays, the standard and rules of reliability appraisal of existing buildings in our country belong to practical appraisal. The method of practical appraisal is developed from the traditional appraising method; it overcomes the shortcomings of the method of experiences evaluation, fully uses modern detection instrument and test technique, applies the theory probability and mathematical theory of statistics and regards the computer as tools. Experts describe, analyze and compute the index items of investigated buildings, give each component's evaluation and conclude comprehensive appraisal of all index items from their overall analysis and argument. This method only can give the evaluation of present state of existing buildings, not predict the failure probability of the existing and servicing buildings. But as the basis of the method of reliability appraisal, the method of practical appraisal is still used in our country's standard and rules.The method of reliability appraisal is on the research stage; the standard and rules of reliability appraisal about existing buildings have been drawn up. However, much more experiences are needed to reach practical stage. For example, some provisions are described only by language. It's very difficult to handle appropriately in appraisal; several intervals were personally given in grade classification, then each interval was classified as a grade. Two little different numbers may be classified different grade in the border of adjacent interval, which caused insurmountable contradiction. In order to overcome un-precision shortcomings that exist in the traditional method of building reliability appraisal. The method of fuzzy comprehensive appraisal is provided to evaluate the reliability of the existing reinforced concrete structure in this paper. It lays the foundation for establishing expert system correspondingly.Fuzziness, fuzzy concept, and theory of membership degree are detailed in this paper, the method by using fuzzy mathematics principle, to choose the fuzzy modification of boundary line of building reliability appraisal and to construct the function of membership...