Modeling fluid pressure effects when cutting saturated rock

• The discrete element method is extended to incorporate pore fluid pressure.
• Method can simulate the effect of hydrostatic pressure in rock cutting process.
• Simulated results match well with hyperbaric rock cutting experiments.

The cutting of saturated rock is of importance to the deep sea mining, dredging and drilling industries. The presence of a fluid in the pores and surrounding the rock can significantly alter the cutting process compared to dry rock cutting through hydrostatic pressure and velocity effects. The discrete element method (DEM) is often used to model rock cutting processes because of its capability to deal simultaneously with deformation, fracturing and fragmentation of the rock. In this paper, a numerical modeling technique to model the cutting of saturated rock is presented. The methodology is based on the DEM, and is extended with a hydro-mechanical coupling of a pore- and ambient fluid. The effects of the fluid pressure are modeled using a smoothed particle (SP) method. Linear rock cutting tests are simulated for various ranges of water depth and permeability of the rock. These results are compared with the available experimental data. The simulations show good resemblance with the experimental results.