This paper presents a 2D numerical simulation of the Hole Erosion Test (HET). The fluid was modeled using SPH-ALE method and a laminar flow was considered. Herein, the pipe walls are made with fixed soil particles. The hydrodynamic forces on the pipe wall particles due to the fluid pressure and to viscosity were evaluated for a given Reynolds number and a given relative roughness. When the pipe opening is small compared to the soil particle size (relative roughness on the order of 50%), the simulations show that the standard deviation of the hydrodynamic forces are of the order of the mean values. Thus, the mean values cannot characterise the fluid loading on the pipe wall particles and the magnitude of the expected erosion process. Moreover, the prominent pipe wall particles induce great pressure contrasts along the pipe wall. Finally, the hydrodynamic forces due to pressure were found much greater than the ones due to fluid viscosity.