Study On Methods Of Multiple Objective Comprehensive Evaluation And Decision-making In The Field Of Bridges Maintenance Management

After thirty years'reform and opening-up, the achievements in bridge establishment have gained world attention. At present, the bridge amount in China has reached about 0.57 million, 0.23 million from 2005 to 2007. With the implement of $4,000 billion investment on economy, the bridge establishment in China will have another developing summit. However, the bridge maintenance management has become obviously heavier, more complicate and difficult due to sudden geographical disaters, daily chaning natural climate, daily increasing traffic flow and dangerous bridge reaching 17% of the total. Therefore, it's necessary to improve bridge maintenance management and to study scientific management of it. The practical meaning is to ensure smooth economic development and social stability. To improve bridge maintenance management, it is necessary to be based on its primary to establish right evaluation on bridge technological status and reasonable decision-making on bridge maintenance management. But the evaluation and decision-making are featured with multi-index, multi-factor and uncertainty, so it is very important to study the adaptable research method which can be applicalbe to the solution of evalution and decision-making on bridge maintenance management.This dissertation adheres to the idea that the theory analysis and method creation are coming from the reality first and then to be put into practice. With the combination of scientific management and bridge maintenance management from the view of evaluation and decision-making and with bridge maintenance management procedure as the clue, four-index evaluation and decision-making model is established to aim at the study and analysis of the overall evaluation on bridge technological situation, decision-making on road-net level bridge maintenance order control, judgment and decision-making on bridge maintenance management project changing and developing and perfomance dynamic evaluation on bridge management system respectively.The bridge technological situation evalution method based on weight comprehensive cloud model cloud model was first proposed. Due to qualitative and quantitive transition of cloud model and uncertainty and taking account of the coexistence of fuzzy and random, and under the condition of short of previous evluative historical data, judgment matrix determining index weight with cloud model was constructed, formula of comprehensive cloud model was promoted, and the method of evaluating the bridge technological situation based on was established. According to the characteristics of bridge technological evaluation, the comprehensive evaluation is more effecitve and closer to pratical evaluation, compared with other two methods.Secondly, Then, the decision-making method on road-net level maintenance order based on nuclear space cloud model was proposed. Cloud model was used to describe the random and fuzzy situation and to judge the optimal value. The nuclear space cloud model order decision-making model was constructed based on the definiton of optimal combination space and cluster center thinking. At the same time, gray-Markov chain which improved situation distribution was established. Hence after, multi-aim planning model for bridge maintenance road-net level was established. As for the application of the method, road-net bridge maintenance order decision-making idex system was established and and the maintenance order was described in nuclear space cloud model.Thirdly, the bridge maintenance chaning management decision on improved rough set was proposed. With comparatively small sample and through vector enlarging method in vector space theory, the algebra structure and vector space theory were combined into rough set theory to establish an improved rough set decision-making method based on algebra. As for the application of the method, the bridge maintenance project changing management decision-making index system studied in this dissertation was established and the index value scale was defined, and the improved rough set model was applied into the decision-making. Compared with other methods, the improved rough set model is effective and feasible. The suggestions and advices were put forward according to the judgment result on project changing and developing trend.Then, the dynamic performance evaluation based on the combination of path analysis and statistics test was proposed. Under the situation of study on cause and effect relationship between index and different analysis on different evaluation results, the hypotheses on different analyzing structure and mean were proposed and the dynamic performance evaluation based on the combination of path analysis and statistics test was put into form based on partial least square-path model. As for the application of the method, aiming at the close relationship between bridge maintenance management level and bridge management system, the performance evaluation index on bridge management system based on users'satisfaction was established, a case being studied by the dynamic evaluation method which combines path model and statistics test. At last, the pinciples, characteristics and applicalbe scales of the above four models were discussed and conclued. From the perspective of bridge maintenance management, suggestions were put forward for the management and development.