中文摘要：

课题组采用四联电动直剪仪对3种沙生植物重塑的根-土复合体及素土进行了直接剪切试验,研究其单根对提高土体残余抗剪强度的影响以及不同孔隙水承压条件下根-土复合体的残余抗剪强度变化。结果表明：浅层土压力下3种植物根-土复合体残余抗剪强度均大于素土,且柠条根系固土效果优于沙棘和白沙蒿;不同含水量梯度下,复合体存在最优含水量,该含水量条件下,根-土复合体强度达到最大值;模拟降雨条件下复合体各残余强度指标均大于非降雨条件下的指标,表现为模拟降雨条件下,3种植物复合体残余粘聚力增长率排序为柠条〉白沙蒿〉沙棘,模拟非降雨条件下排序为柠条〉沙棘〉白沙蒿。上述研究定量分析了3种植物根-土复合材料的力学特性,为水土保持树种的选择提供了理论依据,具有一定的应用价值。

英文摘要：

Root-soil composites of three desert plants and the pure soil were investigated by the fast-shear test using the four joint electric direct shear apparatus to explore the function of single root on improving residual shear strength of root-soil composite and the changes of residual shear strength of root-soil composite under different pore water pressure. The results showed that the residual shear strength of three kind of root-soil composite is greater than pure soil,and the Caragana roots are better than Hippophae rhamnoides Linn. and Artemisia sphaerocephala Krasch roots. The composite exist optimum water content,the intensity will reaches its maximum under this water content. The residual shear strength index under the soil pore water pressure is better than no pore water pressure. Under the soil pore water pressure,the residual cohesion growth rate of three kinds of plant roots-soil composite is Caragana Artemisia sphaerocephala Krasch. Hippophae rhamnoides Linn.,under the no soil pore water pressure that is Caragana Hippophae rhamnoides Linn. Artemisia sphaerocephala Krasch.