根系表皮形态对根-土拉拔力学行为的影响

EFFECT OF ROOT BARK MORPHOLOGY ON THE ROOT PULL-OUT BEHAVIOR IN ROOT–SOIL COMPOSITE

研究选取小叶榕和大叶伞两种植物来开展室内根–土拉拔试验,分析根系的表皮形态及其基本拉伸力学特性对根–土相互作用的影响规律和机理。试验结果表明:两种植物根系拉拔力–位移曲线均呈现3个变化阶段,根–土界面最大摩擦力随根径和法向载荷的增大而增大,根皮粗糙度较大的根系其界面摩擦力较大;随着土颗粒对根皮表面挤压力的增大,表皮粗糙度和拉伸弹性模量共同影响根–土界面的最大摩擦力。相关研究成果可为生态护坡提供科学支撑。

This study used the roots of ficus microphylla and heptapleurum heptaphyllum to conduct the pullout tests for the root–soil composite,focusing on an analysis of the influence of skin morphology and basic tensile mechanical properties of roots on the root–soil interaction.The results showed that the curves of pull-out force vs.displacement for both two types of plant roots display three characteristic stages.The maximum friction force at the root–soil interface increases with the increase of the root diameter and normal load,and the interface friction force between roots and soils is relatively high for the root with more rough bark.With the promotion of extrusion force of soil particles acting on the root bark,the bark roughness and root's elastic modulus jointly affect the maximum friction mobilized at the root–soil interface.The findings in this study can provide a support for the practice of ecological slope protection.