Abstract: In the aim of investigating the anchorage effect of roots of different morphology when functioned as “live nail” within the slope, numerical calculation and analysis was carried out in association with strength reduction method. The influences of number and tiller angle of lateral roots on shallow stability of slope were analyzed. Results of numerical calculation show that vegetation roots have obvious reinforcement effect on shallow slope. Roots could improve the stress state of slope body and control the displacement variable. Safety factors of slope gradually improved with the increases of the number and tiller angles of lateral roots displaying a trend of progressive failure that bulging deformation gradually occurred on the central section and vertical upheaval deformation appeared on the toe area with no reinforcement.

Key words: slope protection by vegetation, roots morphology, numerical calculation, shallow stability, strength reduction method