Abstract: The aim of this research is to compare the influence of root systems of different vegetation types on water transport in slope and shallow soil-stabilizing effect under rainfall condition.The slope reinforced with three different plants’ root system and the unreinforced slope were numerically simulated under intermittent rainfall and heavy rain conditions using a secondary development of FISH programming module of FLAC^3D,and the simulation results were compared with the that of centrifugal model test.The results demonstrated that root system could solidify the soil by preventing from water infiltration.Heart-root-reinforced slope has a entirely different water transport law from plain slope (unreinforced slope) which has a larger water permeation rate of the near-slope surface than that of the far-slope surface.Heart-root system has an optimum transpiration,while plate-root system better resists shallow rainfall erosion and penetration due to its wide wings. In general,heart-root system could reduce the moisture inside the slope body best.The maximum horizontal displacement of taproot,plate-root and heart-root reinforced slope reduce by 52.22%,73.68% and 70.24%,respectively.In conclusion,heart-root system has the best soil-stabilizing effect.In addition,the numerical simulation results are in agreement with centrifugal model test results,which verifies the correctness and effectiveness of the developed program,and lays a foundation for the simulation of more working conditions and more complex root types.

Key words: roots of plants, rainfall, saturated-unsaturated seepage, hydrological effect, reinforcement effect, FLAC^3D