A Method for Determining the Displacement Monitoring Index for Rockfill Dams Considering Material Uncertainty

To consider the influence of material parameter uncertainty on the structural deformation of a dam effectively and to establish a reasonable and reliable safety monitoring index for the displacement of a rockfill dam, a method for determining the displacement monitoring index of a rockfill dam based on stochastic finite element analysis is proposed in this paper. Firstly, uncertainty in the mechanical parameters of the rockfill material is simulated via the correlation log-normal random field, and the statistical characteristics of the dam displacement under the stability of the resultant distribution are obtained through several structural analyses, thus constructing a stochastic finite element method-based monitoring model (SFEMM model); subsequently, the boundary values of the water pressure component are determined based on the statistical characteristics of the displacement at different water levels, and the displacement monitoring index is determined by inputting it into the SFEMM model. Finally, the index is applied to the actual panel rockfill dam project. Finally, the method is applied to the actual concrete-face rockfill dam project. The results show that the SFEMM model achieves higher prediction accuracy and stability than other monitoring models, with the relative error lower than 4.7% and the correlation coefficient higher than 0.96, and the monitoring index is accurate and reasonable. This method provides a scientific and reliable new idea for the safety monitoring of rockfill dams.