植物护坡是一种新型的护坡方式,是很多边坡防治灾害的首选方案。然而在降雨过程中植物的根系可能会诱发沿根系的优势流,使得坡体内孔隙水压力升高,从而降低土体的抗剪强度。另一方面,植物的根系在土中相互缠绕,可增强浅层土体的抗剪强度。在植物护坡过程中到底哪种效应占主导地位目前尚无定论。通过现场试验联合室内三轴试验综合评价植物土体的水力特性和力学特性。首先在室外建立香根草覆盖区、狗牙根草覆盖区和无植被裸土区,在经历一年半自然状态下的干湿循环之后监测3种覆盖区的体积含水率和基质吸力,并计算3个区域的非饱和渗透系数。其次研制取样器并对现场区域的3种土体进行取样,利用现场土样进行三轴剪切试验,研究室外裸土、含狗牙根草土体和含香根草土体的应力–应变关系和抗剪强度指标。同时为了与上述经历干湿循环的土体进行对比,也测量了重塑土的渗透系数和抗剪强度。结果为生态边坡的稳定性研究提供了必要的数据和基础。 Plant slope protection is a new type of slope protection, which is the preferred solution for many slope disaster prevention and control. However, the root system of plants may induce the dominant flow along the root system during the rainfall, which will increase the pore water pressure in the slope and reduce the shear strength of the soil. On the other hand, the root system of plants intertwined in the soil, can enhance the shear strength of shallow soil. In the process of plant slope protection in the end which effect dominates at present there is no conclusion. The hydraulic characteristics and mechanical properties of plant soil were comprehensively evaluated through field test combined with indoor triaxial test. First, vetiver, bermudagrass and uncultivated bare soil areas were established outdoors and the volumetric water content and matrix suction of the three coverage areas were monitored after one and a half years of natural wet and dry cycles, and the calculated Unsaturated permeability coefficient of three regions. Secondly, a sampler was developed and three kinds of soil samples were sampled in the field. Three-axis shear tests were conducted on the soil samples in the field to study the stress-strain relationship between outdoor bare soil, soil containing Bermudagrass and Vetiver grass And shear strength index. At the same time, in order to compare with the above soil subjected to the wet-dry cycle, the permeability coefficient and the shear strength of the remolded soil were also measured. The results provided the necessary data and foundation for the study of ecological slope stability.