Research On Durability Assessment Of Bridge Based On The Fuzzy Theory

Bridge is the hinge of the highway. The carrying and transitable capability of bridge is the key to keep the line smooth. With time going on, more and more bridges will reach or approach their design reference period and the structural damages will appear because of kinds of reasons. Lack of carrying capability, material aging and damages in the existing bridges have been noticed all over the world. Servicing, assessment and reconstruction for existing bridges have become the focus in engineering field. Based on summarizing domestic and foreign results about the assessment of existing bridges, more research on the assessment of concrete-filled steel tubular arch bridge has been accomplished in this thesis. The main contents in this thesis are as follows:1. The connotation and character of the assessment of existing bridge is expounded. The status of research on assessment of existing bridge has been summarized and reviewed.2. According to the analytical hierarchy process, the whole and local model of durability assessment of concrete -filled steel tubular arch bridge has been established in this thesis.3. The theory of fuzzy durability judgement is introduced. By studying the measure against the lost efficacy in fuzzy durability judgement, it has been pointed out that the arithmetic, which operates the fuzzy durability calculation with the operator of product and summation, is fit for the assessment of bridge.4. The thesis has set up the fundamental framework of multilevel fuzzy durability evaluation based on analytical hierarchy process. It has described how to use the method to evaluate the arch bridge in detail. By analyzing the datum in existence and the interrelated criterion, the thesis has put forward the means that can confirm the grade vector of bottom indexes.