(1. Institute of Civil Engineering，Hainan University，Haikou，Hainan 570228，China；2. Northwest Institute of Eco-environment and Resources，Chinese Academy of Sciences，Lanzhou，Gansu 730000，China)
In order to explore the shear strength of the different types of rainforest tree straight roots and soil composite，the research group adapted direct shear tests on shear planes with different the number of root，root diameter and root distribution by designed large complex root-soil direct shear apparatus。Through the electric automotive jack，to push against the upper shear box at a constant speed，in the process of the test always keep a record of the date：jack thrust size，the relative displacement of straight root and shear box，displacement of shear box and so on. Experimental results show that the distribution types of root，root diameter，the number of root and shear depth can effect the shear strength and the shear strength index of the root-soil composite；theroot of vegetation has a positive effect on the reinforcement of soil，The trail lays a foundation for more in-depth research of subsequent tree roots of small landslide governance.
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2017, Vol. 36 
