Evaluation Technology Based On Fuzzy Comprehensive For The Condition Of Existing Bridge In Tibet

Bridges during service in Tibet, suffering arctic-alpine and other adverse effects of the natural environment, inevitably lead to decrease bridge structure carrying capacity and durability, even lead to functional decline of the bridge structure, and operating the conditions can not meet the prescriptive requirements. What's more, regular assessment techniques of the General bridge condition always possess shortcomings of emphasis, so it can not be a comprehensive assessment of those bridges integrated status in Tibet. According to this situation, the paper proposes the assessment techniques of the existing bridges integrated condition in Tibet by the use of AHP and fuzzy comprehensive evaluation method, it can provide a reliable basis of the disposal of existing bridge by the Tibet regional management.This paper gives depth analysis to the major factors of comprehensive condition assessment of existing bridges in Tibet, and proposes the lowest indicator with AHP, and the middle-tier level indicators of five sub-indicators for the comprehensive assessment, which are carrying capacity, durability, functionality, strengthening the economy, and aesthetics of existing bridges, in order to build fuzzy comprehensive evaluation mode based on AHP. According the suggestions from Tibet transportation construction, maintenance departments and well-known experts, and corresponding survey data processing, this paper combines AHP with the basic principles of G1, and gives the weight correction except for the top index weight by the AHP model. Based on the fuzzy theory, this paper establishes the membership function of a single factor, combines with the weight of a single factor, and makes the first fuzzy comprehensive evaluation of the bridges in service. Besides, combined the results of the first comprehensive assessment with the weight factors assignment, this paper makes the second comprehensive assessment and so on, to draw the fuzzy comprehensive evaluation, so as to propose a suitable technology of determining sub-index of existing bridges in the Tibet region. Finally, on the basis of sub-indices identification technology, the paper can give a fuzzy mathematics assessment of general state of bridges during service in Tibet,and make applications of relying project and test.The paper is positive and realistic significance to give a comprehensive assessment of existing bridges in Tibet objectively, to deal with the bridges in service scientifically, to save construction funds and accelerate the pace of road construction, and to improve the quality of road construction and maintenance.