Landslides are catastrophic geophysical phenomena, which may cause heavy fatality and property losses. Hence, it is of vital importance to understand their mechanisms and evaluate their travel distance, so that appropriate measures can be taken to mitigate their risk. This paper reports on an application of the incompressible Smoothed Particle Hydrodynamics (SPH) method to the simulation of the collapse of granular columns onto the planes of different slopes, which is similar to dry landslides. Numerical results show that the non-dimensional runout is a useful parameter in describing the travel distance as it depends only on the initial aspect ratio. Moreover, the traditional model with a constant friction angle is compared with the modified Mohr-Coulomb model with a variable friction angle sensitive to the shear-rate. It is found that traditional Mohr-Coulomb model with a fixed friction angle is incapable of always predicting the correct runout with different combinations of the aspect ratios and inclined angles. The shear-rate dependence effect must be considered for slim granular columns collapsing onto steep slopes. In addition, the taller granular columns travel much further than slowly released columns.