Safety Appraisal On Sluice Gate Based On Modified Fuzzy Composite Appraisal Theory

China is one of the countries that earliest starts construction of hydraulic projects and now possesses the largest number of hydraulic facilities in the world. These hydraulic projects have played a great role in the stable development of national economy and society of China, however, because a large number of projects have been in operation for a long time and were not repaired in time since constructed in 50's and 60's of last century -the early period since the liberation of China, they have now become faulty projects and can not play its due part. The departments concerned have attached importance to these problems and begun to pour a great amount of fund to repair and strengthen them. Being one of the key steps for repair and strengthening, safety appraisal must be completely performed for the strengthening of a hydraulic project Through safety test and analysis, one should get known as in detail as possible the components of a structure, aging state and mechanical properties of materials, structural damages and defects, operation history and actions on structure and perform appraisal on the current safety state of the structure according to relevant standards. Using the fuzzy composite appraisal based on fuzzy mode identification model, the thesis established the index system of safety appraisal for sluice gate according to relevant codes, and then performed a safety appraisal on Sanshenggong Junction Hydraulic Project on the Yellow River on the basis of investigation of the current project state, in-situ safety test and project recheck by the Ministry of Water Resources of China and China Institute of Water Resources and Hydropower. The thesis applied the modified fuzzy mathematic theory and method to the safety appraisal of sluice gates, which not only considered a large number of and multiple-level influencing factors determining the safety category but also quantitatively expressed the subjective judgement so as to quantify the quality indexes and mathematically model the appraisal process. The results agree with that obtained by the method of expert experiences.