刺槐根系抗弯特性研究

从根径和坡位两方面研究了石质陡边坡刺槐根系的抗弯特性。通过对刺槐根系进行室内单根弯曲试验,分析了不同坡位下坡向侧根的抗弯特性。试验结果表明,根系的抗弯强度与坡位的关系显著,不同坡位抗弯强度关系为:坡顶>坡中>坡底。坡顶和坡底根系的抗弯强度与根径之间存在递增的幂函数关系,而坡中根系抗弯强度与根径之间的关系不显著。弯曲弹性模量与根径存在递减的幂函数关系,在根径大于8mm左右,不同坡位根系弯曲弹性模量大小关系为:坡顶>坡中>坡底。不同坡位根系的最大弯曲力之间差异不显著,最大弯曲力沿着坡面向下呈递减趋势。不同坡位根系的断裂挠度之间差异也不显著,但根系的断裂挠度沿着坡面向下呈递增趋势。综合这些结果,可以发现坡顶根系的抗弯性能最佳,对边坡稳定的贡献较大。

Anti-Bending Characteristics of Robinia Pseudoacacia L. Roots

In order to investigate the variations of root characteristics in terms of anti-bending with changes of root diameter and slope position,a total number of 36 Robinia pseudoacacia L.trees on a steep rocky slope were selected and root samples were collected.Anti-bending forces of the root samples were measured using an electronic universal testing machine.The results show that the relationship between anti-bending capability and slope position was significant.Root anti-bending capability decreased from upper-slope position to the down-slope position.For roots in the upper and the lower slope positions,the relationship between bending strength and root diameter can be described by a power function,and root tolerance of bending increased with root diameter.As for the roots collected in the mid-slope position,there was no significant relationship between bending tolerance and root diameter.Root flexural modulus decreased as root diameter increased,which can also be described by a power function.Flexural modulus decreased from the upper slope to the down slope for roots with diameters greater than 8 mm.Maximum anti-bending forces and fracture deflections of the roots did not differ significantly among the three slope positions.The former decreased from the upper slope towards the down slope,while the latter increased from the upper to down slope.In conclusion,the roots in the upper slope had the strongest bending resistance,which contributed most to the slope stability