Abstract: An ideal slope model of open-pit mine dump was established to investigate the influence of two plant roots,i.e.,Periploca sepium Bunge (shrub plant) and Conyza canadensis L. Cronq. (herb plant),on the stability of shallow slope. The west dump of Haizhou open-pit mine was selected as the research site. The distributions of root area ratio (RAR) on soil profiles at different depths (2,4,6,8,10,12 and 14 cm) were determined by using image processing technology;the tensile properties of the roots of the two plants were measured by a tension meter. Furthermore,the additional cohesion of roots on soil profiles at different depths was quantified by using the fiber bundle model. Results showed that the average RAR of the two plant roots decreased with the increase of soil profile depth,and the RAR of each individual plant root varied significantly at different soil profile depths. The relationship between tensile force and diameter of the two plant roots showed a power law function,and the tensile force of Conyza canadensis L. Cronq. root was higher than that of Periploca sepium Bunge root given the same diameter. Moreover,the additional cohesion of the roots of the two plants decreased with the increase of depth,displaying significant differences at various depths. The data dispersion of RAR and additional cohesion attenuated with the increase of root depth. In conclusion,the root systems of the two plants have obvious reinforcement effects on the slope. The safety factors of slopes reinforced by Periploca sepium Bunge and Conyza canadensis L. Cronq. increased by 5.4% and 9%,respectively.

Key words: root reinforcement, root distribution characteristics, additional root cohesion, shallow slope stability, safety factor