Uncertainty is inevitable in the safety monitoring and evaluation process of earth-rock dam. Such uncertainty makes the accurate reflection of the running status of earth-rock dams of traditional safety assessment results impossible. Thus, this study proposed a safety assessment model of earth-rock dams based on the combination weighting method of ideal point and the cloud theory model. The proposed model was used to scientifically solve the uncertainty during the safety assessment of earth-rock dams. Real and reliable weights of indexes were determined using the combination weighting method based on the ideal point. Then, the safety evaluation grade ranges of each evaluation index were divided on the basis of the measured data. These grade ranges were "softened" by combining cloud theory. The proposed safety assessment model was applied to an earth-rock dam in the reservoir of a pumped storage station in Tai'an City, Shandong Province, China. Results demonstrate that: (1) the proposed model can effectively solve fuzzy and random problems during the safety assessment of earth-rock dams, and (2) the results show that the safety of the investigated earth-rock dam is in a normal running state. This outcome reflects the actual conditions of the earth-rock dam. The proposed model provides references in the diagnosis and decision making in the earth-rock dam management department.

The key to simulating the mechanical properties of earth-rockfill dam materials is selecting a reasonable constitutive model. The traditional constitutive model targets specific earth-rockfill dam materials and involves many hypotheses in theory, resulting in large common errors in applications. The Pastor-Zienkiewicz model (P-Z model) based on generalized plastic mechanics theory has a strict theoretical base, but it involves many parameters. Moreover, the determination of parameter a entails high discreteness because of experimental conditions, and this discreteness influences the accuracy of simulation analysis. The mechanical properties of earth-rockfill dam materials were simulated using the P-Z model in this study to optimize parameter a of the model and decrease its discreteness. First, conventional triaxial shear test results of earth-rock materials were denoised with the empirical mode decomposition method. Second, a method to optimize parameter a was proposed by using cloud theory. Lastly, a numerical simulation analysis of the triaxial shearing test was performed with the optimized P-Z model. Research results demonstrate that the entropy error and hyper entropy error rates of the triaxial shearing test data decline by 35% and 67%, respectively, and the cloud droplet range of parameter a is narrowed by 32%. The discreteness of the values decreases significantly. The simulation calculation results are consistent with the test results, thereby confirming the reasonability of the proposed parameter optimization method. The optimized P-Z model can simulate the mechanical properties of earth-rockfill dam materials accurately. This study can provide a theoretical reference for finite element simulation analysis of earth-rockfill dam structures.