Reserch On Comprehensive Evaluation's Membership Grade And Weight Based On Sea Wall Safety Monitoring

Engineering safety monitoring has widespread applications in many engineering field and the safety evaluation work for data monitoring attracts more and more attention. Sea wall safety monitoring system becomes more and more complete due to the execution of sea wall construction management. The safety evaluation work, based on the data of safety monitoring, has become one of the most important ways for sea wall manager to guarantee the normal operation of sea wall. It also helps the sea wall manager to conduct the analysis, judgment, instruction guidance and maintenance of sea wall status.For accurate analysis of data monitoring information during sea wall operation and for more reasonable evaluation of sea wall safety, this paper carries out the analysis for sea wall comprehensive evaluation system by utilizing the fuzzy mathematics synthetic evaluation system. This paper also classifies the safety evaluation factor according to the monitoring data. Further more, this paper develops detailed study and gives illustration on the determination of weight and membership grade in the sea wall fuzzy comprehensive evaluation.In the evaluation of sea wall safety, different evaluating factors have different safety sense, thus, the safety standard classification is different, which directly determines the different methods for the calculation of membership grade of various factors. In the sea wall safety evaluation, this paper classifies the safety level based on the evaluating factors such as sea level and rainfall, and calculate the membership grade of various safety level by fuzzy statistics. The safety definition of the evaluating factor osmosis is different from the other factors, and it does not have any characteristic. This paper classifies the safety level of osmosis by using the probability theory and integrating the confidence level, and at the mean time, this paper calculate the membership grade by using membership functions which match the normal distribution.There are two methods to identify the weight of evaluating factors, subjective weight assignment method and objective weight assignment method. This paper utilizes the analytical hierarchy process of subjective weight assignment method and the principle component analysis and entropy weight assignment of objective weight assignment method. In the study, the principle component method is improved. Based on the original fundamentals, the payload and contribution rate are introduced to the weight assignment and a new weight assignment method based on the principle component idea is proposed. Entropy weight assignment is a frequently used weight assignment method too, and its usage needs the integration of the characteristic of monitoring data. This paper performs detailed analysis on the evaluating factors and the feature of entropy weight method, and finally combines them together which provides a trial for the sea wall evaluation.The above mentioned evaluating processes are all obtained through cases which based on the monitoring data of Pudong sea wall operation period. The analysis indicates that the evaluating model is reasonable and the methods are applicable. The case results can objectively reflect the safety status and has strong forecasting and sensitive features. These evaluating methods provide efficient tools for the data analysis of future sea wall safety monitoring and sea wall safety assurance.