摘要
通过在植被混凝土基材上对狗牙根和紫花苜蓿2种有代表性的草本植物进行样地种植和室内直剪试验,分析植被混凝土基材上不同深度根-土复合体抗剪强度的分布规律,对比基材空白样地相应深度的抗剪强度,证实和量化了草本植物根系增强土壤抗剪切强度的作用。试验表明:根-土复合体在0-10cm土层内摩擦角变化不明显,粘聚力随深度先增大后减小;与基材空白样样地相比,根-土复合体内摩擦角变化不大,粘聚力变化显著,狗牙根粘聚力最大增幅为129.4%,紫花苜蓿粘聚力最大增幅为77%;狗牙根根-土复合体抗剪强度比同期生长的紫花苜蓿根-土复合体的抗剪强度高。
Two representative herb plants Bermuda grass and Medicago sati are planted in the vegetationgrowing concrete base material in the testing areas,then direct shear tests on the unplanted soil and root-soil composite system are conducted.The distribution pattern of the anti-shearing strength of root-soil composite system with increasing depth in different soil layers is studied.By comparing the shear strength indexes of the soil without roots and two kinds of soils with roots,the mechanical effects of the root-soil composite system of two herb plants with six-month growth period can be verified and quantified.The results showed that the variation trend of the cohesion in different soil layers of the root-soil composite systems increased in 2-4 cm soil layer and then it decreased,and there were no apparent changes in the internal friction angle with the depth increase of the soil.Compared with the cohesion of soil without roots,the maximum increasing amplitudes of the cohesion of Bermuda grass and Medicago sati were 129.4%and 77.0%,respectively.The antishearing strength of root-soil composite system of Bermuda grass was better than that of Medicago sati after six-months growth period.
出处
《水土保持研究》
CSCD
北大核心
2010年第4期158-161,165,共5页
Research of Soil and Water Conservation
基金
国家自然科学基金项目(50879043)
国家科技支撑计划项目(2006BAC10B04)
关键词
根-土复合体
抗剪强度
粘聚力
内摩擦角
root-soil composite system
anti-shearing strength
cohesion
internal friction angle
