Process Simulation and Mesoscopic Analysis of Rockfill Dam Compaction Using Discrete Element Method

Abstract

To investigate the mesoscopic mechanism of rockfill dam material compaction, the discrete element method is used to simulate the entire compaction process. An irregular aggregate model is first established using laser scanning technology, and an accurate method for determining the load of a roller is proposed. The entire construction process of the rockfill dam—including the dumping, paving, and compaction phases—is then simulated using a two-dimensional (2D) particle flow code model, and a quantitative relationship between the porosity of the 2D model and the actual porosity is proposed for analyzing the influence of different compaction parameters and the motion law of the aggregate. The results show that the compaction effectiveness of the dam material improves with decreasing roller velocity and lift thickness, as well as with an increase in the excitation force. It is shown that the vertical acceleration of the particles decreases exponentially along the depth. Furthermore, the vertical velocity of the particles decreases with increasing compaction passes at the same depth, while the rate of increase in the vertical displacement of the particles decreases. During the compaction settlement process, the contribution of small particles is more apparent than that of larger particles. The mesoscopic mechanism of rockfill dam material compaction is analyzed, and a basis for reasonably selecting the compaction parameters and gradation is derived. Moreover, this method is less time-consuming and labor-intensive and costs less than conventional compaction experiments.