Abstract: Based on Terzaghi consolidation theory, for a saturated dump foundation, the variation of excess pore water pressure and settling volume with time under unidirectional loading was calculated by using analytical solution. At the same time, the fluid-structure interaction during settlement in this foundation was simulated with seepage module in FLAC^3D. Results showed that the settlement volume from FLAC^3D was consistent with that from analytical solution under unidirectional consolidation, indicating that the seepage module could be reliable to simulate consolidation settlement in dump foundation. Then, a vertical sand drain was added in dump foundation, and the dissipation simulation of excess pore water pressure was done based on sand drain consolidation method. Results showed that the consolidation time was markedly shorted after sand drain treated compared with natural settlement, which meant sand drain in dump foundation could greatly promote open-pit mine continuing production.