作 者：
储怡鑫;薛凯喜;冯国建;朱小伟;王瑞洋;刘欣
单 位：
昆明学院建筑工程学院;东华理工大学土木与建筑工程学院
关键词：
根系力学特性;茎杆力学特性;根土复合体;苏门白酒草;紫茎泽兰;鬼针草
摘 要：
本文以云南省昆明市官渡区宝象河经开区河道作为研究区,选取紫茎泽兰(Eupatorium adenophorum)、苏门白酒草(Conyza sumatrensis)、鬼针草(Bidens pilosa Linn) 3种分布广泛的草本植物进行根系及茎杆的力学特性试验研究,探讨3种植物在河道边坡防护中的内在机理。在分析取样点土壤性能以及对植物样本草本属性对照的基础上,进行植物抗拔试验、茎杆抗弯试验、单根抗拉试验和根土复合体试样直接剪切试验。结果表明,3种草本植物平均抗拔承载力由大至小依次为:鬼针草(34.69 N)、紫茎泽兰(32.50 N)、苏门白酒草(23.14 N),抗拔承载力与根系质量及地上部分质量均呈正相关,关系可由幂函数、修正的幂函数、指数函数进行拟合;平均茎杆抗弯强度由大至小依次为:紫茎泽兰(5.18 MPa)、鬼针草(5.01 MPa)、苏门白酒草(2.63 MPa),茎杆直径与抗弯强度呈负相关,关系可由指数函数拟合;平均根系抗拉力由大至小依次为:紫茎泽兰(9.26 N)、苏门白酒草(8.54 N)、鬼针草(5.68 N),平均根系抗拉强度由大至小依次为:紫茎泽兰(33.87 MPa)、鬼针草(32.74 MPa)、苏门白酒草(22.19 MPa),根系直径与抗拉力、抗拉强度的关系分别呈正相关与负相关,可分别由指数函数、幂函数拟合;根土复合体的黏聚力呈逐渐增大的变化趋势,苏门白酒草、紫茎泽兰、鬼针草涨幅相对于纯土分别为90%、120%、123%,内摩擦角呈逐渐缓慢增大的趋势,苏门白酒草、紫茎泽兰、鬼针草涨幅分别为5%、10%、12%,在100、200、300、400 kPa的垂直压力下,3种植物的根土复合体抗剪强度相较于纯土均有大幅上涨,剪切位移与剪切应力关系曲线近似于幂函数。
译 名：
Experimental Study on Mechanical Properties of Roots and Stems of Three Herbaceous Plants in Kunming
作 者：
CHU Yixin;XUE Kaixi;FENG Guojian;ZHU Xiaowei;WANG Ruiyang;LIU Xin;School of Civil and Architectural Engineering, East China University of Technology;College of Architecture and Civil Engineering, Kunming University;
关键词：
Mechanical properties of root system;;mechanical properties of stem;;root-soil complex system;;Conyza sumatrensis;;Eupatorium adenophorum;;Bidens pilosa Linn
摘 要：
Taking Baoxiang River in Guandu District, Kunming City, Yunnan Province, as the research area, three widely distributed herbaceous plants, Eupatorium adenophorum, Conyza sumatrensis, and Bidens pilosa Linn, were selected for experimental research on mechanical properties of roots and stems, and the internal mechanism of three plants in river slope protection were explored. Based on the analysis of soil properties of the sampling points and herbal attribute comparison of plant samples, plant stem pull-out test, bending test, single tensile test and complex root soil sample direct shear test were carried out. The results showed that the average uplift capacity of the three herbaceous plants arranged in a descending order was Bidens pilosa Linn(34.69 N), Eupatorium adenophorum(32.50 N), and Conyza sumatrensis(23.14 N). The uplift bearing capacity was positively correlated with the quality of root system and above-ground part, and their relationship can be fitted by power function, modified power function and exponential function. The average stem bending strength shown in a descending order was Eupatorium adenophorum(5.18 MPa), Bidens pilosa Linn(5.01 MPa) and Conyza sumatrensis(2.63 MPa). The stem diameter had a negative correlation with the bending strength and its relationship can be fitted by an exponential function. The average root tensile stress in descending order was Eupatorium adenophorum(9.26 N), Conyza sumatrensis(8.54 N) and Bidens pilosa Linn(5.68 N). The average root tensile strength in descending order was Eupatorium adenophorum(33.87 MPa), Bidens pilosa Linn(32.74 MPa) and Conyza sumatrensis(22.19 MPa). The root diameter was positively correlated with the tensile stress, while it was negatively correlated with the tensile strength. Both the two relationships can be fitted by exponential function and power function respectively. The cohesive force of the root-soil complex showed a gradually increasing trend. The increase of Conyza sumatrensis,Eupatorium adenophorum and Bidens pilosa Linn was 90%,120%,and123% respectively,when compared with pure soil. The internal friction angle showed a slowly increasing trend,as Conyza sumatrensis,Eupatorium adenophorum and Bidens pilosa Linn rose by 5%,10%,and 12% respectively. Under the vertical pressures of 100,200,300,and 400 k Pa,the shear strength of the root-soil complexes of the three plants increased significantly when they were compared with pure soil,and the relationship between shear displacement and shear stress was similar to a power function.
