摘要
【目的】对比分析带根原状土和无根素土的强度机理,探明根系对根-土复合体强度的影响规律。【方法】选取模型箱中不同深度的带根原状土和无根素土分别进行了室内直剪试验。【结果】草本植物根系对土体具有明显的加筋作用,在相同条件下,带根原状土黏聚力明显高于同一深度的无根素土。与无根素土相比,带根原状土抗剪强度的增加主要体现为黏聚力的增加。随着土层深度的增加,根系密度逐渐下降,在此基础上,分别提出了根-土复合体的黏聚力与土层深度和根系分布密度的关系式。其中根-土复合体的黏聚力呈二次抛物线递减,根土复合体的黏聚力随土体中的根系分布密度的增大而呈幂函数形式增大。【结论】在进行植物护坡时,为了获得更好的固土能力,应该尽可能地选取根系密度较大根系较长的植物。
【Objective】Analyse the strength of the undisturbed soil and rootless soil mechanism,and explore the composite displine of root and strength.【Method】The indoor direct shear tests were carried out on with different depths roots and rootless soil in the model box respectively.【Result】The strengths of soils were reinforced obviously,when the roots of herbaceous plants were existed in these soils.Under the same conditions,the cohesive force of the undisturbed soil with roots was obviously higher than that of the rootless soil at the same depth.Furthermore,compared with the rootless soil,the increasing of shear strength of undisturbed soil with root was mainly attributed to the increasing of its cohesion.With the increasing of soil depth,the density of root was decreased gradually.And on the basis relation between cohesion of root-soil composite and soil depth,and the relation between cohesion and root distribution density were put forward respectively.The cohesion of root-soil composite was decreased in the form of second degree parabola.The cohesion was increased in the form of power function with the increasing of root distribution density in the soil.【Conclusion】In the process of plant slope protection,in order to obtain better soil fixation ability,plants with longer roots with higher root density should be selected as far as possible.
作者
包嘉邈
肖宏彬
李珍玉
徐安东
张韬
BAO Jiamiao;XIAO Hongbin;LI Zhenyu;XU ANDong;ZHANG Tao(College of Civil Engineering,Central South University of Forestry and Technology,Changsha 410004,China)
出处
《灌溉排水学报》
CSCD
北大核心
2018年第S1期87-90,共4页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目(51608545
31270671)
关键词
香根草
根-土复合体
根系密度
生态护坡
vetiver grass
root-soil composite
root density
ecological slope protection
