Investigation of Submerged Soil Excavation by High-Velocity Water Jet Using Two-Fluid Smoothed Particle Hydrodynamics Method

In this paper, submerged soil excavation by high-velocity water jet was investigated by means of a two-fluid smoothed-particle hydrodynamics (SPH) method. A critical state theory was coupled to account for the dilatancy or compaction of the soil subjected to deformation. Numerical simulations for excavations by plane wall jet and vertical impinging jet are presented. The development of the crater size during the jetting process was obtained and found to be qualitatively in agreement with experimental observations and numerical simulations provided by other researchers. The effects of the nozzle width, impinging height, jetting velocity, and water flux on the formation of different crater patterns were examined. The effects of soil parameters, such as cohesion [in the range of (0, 25 kPa)] and dilatancy, were also investigated. Computational results illustrate the critical role of dilatancy in the coupling evolution of the solid volume fraction and pore fluid pressure by modifying the Coulomb friction and thereby regulating the dynamics of soil deformation. The proposed method is robust and efficient, and can be applied to water-soil mixture flows in subsea engineering and geomechanics.