中文摘要：

通过在道路边坡进行植物防护和原位剪切试验，研究了不同植被防护措施对边坡抗剪强度（τ）影响。结果表明，植被根系随土壤深度增加而减少，表层（0～10cm）根系长度密度（Rootlengthdensity，RLD）占总RLD的34％～78％；植被根系含量及盖度与土壤水分含量（Soilwatercontent，SWC）呈指数正相关。表层（0～10cm）土壤抗剪强度主要受植被根系及盖度影响，随着根系长度密度（RLD）、根系重量密度（Rootweightdensity，RWD）、植被盖度（VegetationCover，VC）增加呈指数形式增大。30cm深度土壤抗剪强度值显著低于10cm值和50cm值。随着土壤深度增加，土壤容重和水分对抗剪强度影响力增大，在50cm处两者分别与抗剪强度呈线性正相关和指数负相关关系。

英文摘要：

To study effects of roadside slope vegetation restoration on shear strength （τ） of and surface soil loss from the slopes, seven vegetation restoration models were adopted in in-situ shearing tests. It was found that vegetation root sys- tems decreased in density with increasing soil depth, the root length density （RLD） in the 0 - 10 cm soil layer accounted for 34% - 78% of the total RLD And the vegetation root magnitude was positively related to soil water content （SWC） showing a exponential funetion correlation. Shear strength of the surface soil layer （0- 10 cm） was mainly affected by vegetation root systems and vegetation coverage and increased as a exponential function of RLD, root weight density （RWD） and vegetation cover （VC）. The controlling factors on τ varied with soil depth, and regression analysis showed RLD, RWD and VC had statistically significant effects on τ in the 10 cm soil depth. However, none of the predominant factors on T were founded in the 30 cm soil depth, which was so defined as a transition layer and was the lowest shear strength τ as compared with the 10 em and 50 cm soil depths. The influence of soil bulk density （ρ） and SWC got bigger on τ with soil depth, showing a positive linear relationship and a negative exponential function relationship, respectively in 50 cm soil depth.