摘要
植被根系的力学性质对于斜坡的稳定性是一个重要因素。为确定油松根系的基本力学特性,对油松不同标距不同直径根段进行拉力试验。结果表明:所有根系随直径级的增大,抗拉力以幂函数显著增大,抗拉强度却以幂函数减小,对于直径D≤1mm的根系,抗拉强度显著增加。标距对抗拉力影响不显著,对抗拉强度影响显著。油松的应力应变曲线为单峰曲线,具有弹塑性材料特征。首次初步将油松根系的应力应变曲线简化为3个阶段:线性弹性段、非线性弹性段和塑性段。在理论推导和数据分析的基础上,建立了油松根系的三阶抛物线本构模型。这些研究探明了油松作为水土保持先锋树种固土的力学机理,对护坡植物的选择和优化组合具有重要的参考价值。
Vegetation root mechanical property is an important factor for slope stability.In order to determine the basic mechanical properties of Pinus tabulaeformis roots,root specimens of different lengths and different diameters were carried out for tensile test.Results showed that ultimate tensile force increased with increasing diameter according to a power function,but tensile strength decreased as so,with a sharp increase of tensile strength in roots with a diameter ≤1 mm.Root lengths had a significant effect on tensile force,against a significant influence on tensile strength.Root stress-strain curve of Pinus tabulaeformis all was a single-peak curve with elastic-plastic material characteristics.The stress-strain curve of root was first simplified into three stages：Linear elastic stage,non-linear elastic stage,plasticity stage.Moreover,based on theoretical derivation and data analysis,root constitutive model of third order parabola of Pinus tabulaeformis was established.It had researched mechanics mechanism of Pinus tabulaeformis as water and soil conservation pioneer species for soil enforcement,which had important reference value for choosing and optimizing slope protection plant.
出处
《水土保持学报》
CSCD
北大核心
2011年第5期17-20,25,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(30872067)
教育部博士点基金(20090014110002)
青年科学基金项目(30901162)
关键词
油松根系
抗拉力
抗拉强度
应力应变曲线
本构模型
Pinus tabulaeformis roots
tensile force
tensile strength
stress-strain curve
constitutive model
