土壤孔隙水承压条件下4种根—土复合体抗剪特性  

Shear Strength Characteristics of Root—Soil Composites Under Bearing Pressure Condition of Soil Pore Water

作　　者：张欣[1] 姚喜军[2] 刘静[2] 王林和[2] 尹瑞平[1] 邢会文[2] 金彩霞 

机构地区：[1]水利部牧区水利科学研究所,内蒙古呼和浩特010020 [2]内蒙古农业大学生态环境学院,内蒙古呼和浩特010019 [3]包头市达茂旗畜牧业局草原工作站,内蒙古包头014500

出　　处：《水土保持通报》2010年第4期22-26,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金"采煤塌陷区植物固土抗蚀生物力学特性的研究"(90610008);中国水科院科研究专项"风水复合侵蚀下灌木根系固土作用研究"

摘　　要：采用直剪仪对4种沙生植物重塑的根—土复合体及素土进行快剪试验,探讨了其抗剪强度以及根径和垂直压力对抗剪强度的影响。结果表明,柠条、沙柳、沙地柏、白沙蒿根—土复合体在1.5m(25kPa)的浅层土体范围内抗剪强度均大于素土,4种植物根—土复合体的内摩擦角与素土相比差异不明显;在根径相同(1.25mm)的情况下,4种植物根—土复合体的黏聚力均大于素土,其黏聚力增加率的变化范围在4.60%～46.23%之间,大小顺序为:柠条>沙地柏>沙柳>白沙蒿;4种植物随着根径的增加,复合体的抗剪强度均有不同程度的增大。Root-soil composites of four desert plants and pure soil were investigated by fast-shear test using direct shear apparatus to explore shear strengths of root—soil composites and the impacts of root diameter and vertical pressure on shear strength. Results showed that shear strengths of the root—soil composites for Caragana microphylla Lam.,Salix psammophila,Sabina valgaris Ant.,and Artemisia sphaerocephala Krasch. are higher than shear strength of pure soil within 1.5 m shallow layer（25 kPa）. Equivalent friction angles of the root—soil composites do not change obviously as compared with pure soil. For the same diameter （1.25 mm）,cohesive forces of the root—soil composites are greater than pure soil and the range of increased cohesion is 4.60%～46.23% and by the cohesion,the order of the plants is Caragana microphylla Lam.〉Sabina valgaris Ant.〉Salix psammophila〉Artemisia sphaerocephala Krasch.. Shear strengths of the composites are increased to different extents when root diameter is increased.

关 键 词：根—土复合体 抗剪强度 黏聚力 内摩擦角 

分 类 号：S157[农业科学—土壤学] Q947.6[农业科学—农业基础科学]