(1. Center for Post-doctoral Studies in Crop Science，Qinghai University，Xining，Qinghai 810016，China；2. School of Civil Engineering and Architecture，Shaanxi University of Technology，Hanzhong，Shaanxi 723000，China；3. School of
Mathematic and Computer Science，Shaanxi University of Technology，Hanzhong，Shaanxi 723000，China；
4. Department of Geological Engineering，Qinghai University，Xining，Qinghai 810016，China)
Abstract：To investigate the impact of gauge length on the tensile mechanical indices of roots，Elymus nutans was selected as the tested objects due to its narrow variation in its diameter. After that，tension test was conducted on
the roots with its gauge length of 20，40 and 80 mm，and meanwhile tensile resistance，tensile strength，tensile strain and tensile modulus of the roots as well as its diameter were also measured. Built on these results，one-way analysis of variance(One-way ANOVA) was conducted to investigate the impact of gauge length on the tensile mechanical indices of roots，in which gauge length was taken as the independent variable and other indices as tensile resistance，tensile strength，tensile strain and tensile modulus were taken as dependent variables. And then Normal distribution，Lognormal distribution and Weibull distribution were introduced to describe the distribution of these indices. The results show that tensile resistance，tensile strength and tensile strain exhibit a decreasing trend with gauge length decreasing，while tensile modulus exhibits an opposite trend，gauge length exerts no impact on the relation between root diameter and its tensile mechanical indices. Normal distribution，Lognormal distribution and Weibull distribution could be used to describe the distribution of the tensile mechanical indices for E. nutans. The optimal distribution for both root diameter and its tensile modulus is normal distribution，and the optimal distribution for tensile resistance is Weibull distribution，indicating that the optimal for these indices is independent on gauge length，whereas the optimal distribution for tensile strength is Normal or Weibull distribution，and the optimal distribution for tensile strain is Lognormal or Weibull distribution，indicating that the optimal distribution for the two indices(tensile strength and tensile strain) are dependent on gauge length. Negative correlations between tensile resistance，tensile strength，tensile strain，and gauge length was discovered，whereas a positive correlation between tensile modulus and gauge length was found. This finding can be used to widen and deepen the theory of slope protection by vegetation，and meanwhile this conclusion has a theoretical significance and practical value in preventing soil erosion，shallow landslide and other geological hazards in areas suffering from severe soil erosion and shallow landslides.
付江涛1，2，李晓康3，刘昌义4，郭 鸿2，刘亚斌4，李世珍4，鲁秋菊3，胡夏嵩4，. 标距对垂穗披碱草根系抗拉特性影响统计研究[J]. 岩石力学与工程学报, 2021, 40(S2): 3399-3413.
FU Jiangtao1，2，LI Xiaokang3，LIU Changyi4，GUO Hong2，LIU Yabin4，LI Shizhen4，LU Qiuju3，HU Xiasong4，LI Guorong4，LU Haijing4，ZHU Haili4. Impact of gauge length on the tensile mechanical indices of roots for Elymus nutans based on statistical theory. , 2021, 40(S2): 3399-3413.
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2021, Vol. 40 
