Study On Grey Comprehensive Appraisal Models For Dam Safety Monitoring

The Grey System Theory is applied to analyze the deformation condition, structure behavior and safety behavior of dams combined mathematics, mechanics and dam engineering knowledge. In this paper, some new effective models and methods are presented. The main contents are described as follows:1. On the basis of analyzing the theoretical background of grey models and current grey models, the procedure for building GM(1,N) Model is proposed. For it has some disadvantages, this model is improved by using correlative degrees. The study shows that the precision of the improved model is better than the stepwise regression model.2. Because the precision of SCGM(l,h)c Model is not satisfactory in some situations, the way of building SCGM(l,h)c Model utilizing residual error series is presented to correct the former SCGM(l,h)c Model. The merit of the improved model is revealed by the example in this paper.3. Both parameters and observed values are considered as grey in dam safety monitoring models. Grey parameters are identified by the means of the Grey System Theory and then forecasting values are given hi the format of grey interval.4. Based on the Control Theory, the Grey Process Model is built using the displacement of the dam crest and the stress of the dam heel, and the model can be used to analyze the structure behavior and stability of dams.5. Utilizing the grey clustering method, mathematics and mechanics knowledge, the safety states of dams under typical load combinations are analyzed and evaluated.6. Based on the grey clustering method, the forecasting model of dam safety monitoring values is built. By using the model, dam safety monitoring values can be forecasted by environmental values and the result is satisfactory.