中文摘要：

通过对香根草和小叶女贞两种不同植物根系构成的根土复合体及两种植物混交根系构成的根土复合体分别进行了系列直剪试验研究,探索了在不同含水率及不同含根比的情况下,植物根系对复合体抗剪强度的影响规律。研究表明,草本植物香根草以及木本植物小叶女贞的根系都能提高根土复合体的抗剪强度,但二者对复合体抗剪强度指标的贡献是不同的,且混交根土复合体的抗剪强度仍符合库伦强度理论。在此基础上,本研究提出了根土复合体的内摩擦角随小叶女贞含根比变化的幂函数关系式。以上研究为进一步探索林草一体化高稳定护坡技术,具有重要的理论意义。

英文摘要：

Through a series of indoor shear tests,the effect laws that the two kinds of plants（vetiver grass and Ligustrum quihoui） each roots and mixed forest roots influencing on the shear strength of root-soil composites were studied.Under the conditions of different root contents and different water contents,the shear strengths of these composites which contain different kinds of roots have been tested respectively.The roots included in these composites are vetiveria’s roots or privet’s roots（L.quihoui） or the roots of mixed the two plants.The results indicate that either of the two plants’ roots can increase the shear strength of the soil,but different plants’ roots,their contributions to the composites shear strength indexes were varied.Furthermore,the shear strength of roots-soil composites still conformed to Coulomb’s strength theory;on this basis,a power function which can be used to describe the relationship between the internal friction angle of the complex and privet’s roots contain has been presented.In order to explore high stable slope protection technology of forest-grass integration,the results of this study may have important theoretical implications for future research.