Numerical Studies on Filter of Piping in Broadly Graded Cohesionless Soils
China is one of the countries that suffers from severe flood casualties and the piping disaster is catastrophic. To explore the piping mechanism, putting forward a valid piping prevention measure has great significance. Due to the complexity of piping, study on the mechanism is still in controversy although it has been on for more than one hundred years. Therefore, more precise analysis is required to clarify the filter prevention piping mechanisms. Because of comprehensive study on the documentations and generalizing the research founding of predecessors and their shortage, an analytical model taking the large deformation of medium and coupling of fluid and solid into account is established to simulate a base soil-filter system during seepage in broadly graded cohesionless soils by using and developing the PFC3D program based on discrete element method. The model shows that the key point of piping control is locating the filter, and the factor between layers is important for the effectiveness of the filter. The model predictions are also compared with the available empirical recommendations. On a series of base material, laboratory tests verify the validity of the model.
Keywords: DEM, Discrete Element Method, Simulation, PFC3D, Cohesion, Filter, Piping, Soils