土壤含水率与干密度对油松根-土界面摩擦性能的影响

为研究土壤物理特性对植物根系固土性能的影响,通过对油松单根施加拔出荷载进行直接拉拔实验,分析土壤含水率与干密度对拔出过程中根-土界面摩擦性能的影响。结果表明：单根拉拔实验中根系有被拔出和被拉断2种破坏模式：根-土最大摩擦力与根系直径有明显的线性相关关系,通过建立单根简化模型分析根-土间的摩擦情况,证明与实验结论一致;且根系直径在一定范围内时,根-土的最大摩擦力随土壤含水率的升高先增大后减小,而随土体干密度的升高单调增大。

Effects of moisture content and dry density of soil on the friction characteristics between Pinus tabulaeformis root and soil

In order to evaluate the effect of the different soil physical characteristics on soil reinforcement by plant roots,the experiment of directly pulling out single roots of Pinus tabulaeformis was conducted by implementing pull-out load,and the effect of the different soil moisture contents and dry densities on the friction performance between tree roots and soil system was tested. The results showed that the test of directly pulling out single roots had two main failure modes： pulled out and broken,and there existed a significantly linear correlation between root diameter and root-soil friction. We analyzed the friction between roots and soil by establishing a simplified single-root model,and the results agreed with the experimental conclusion. In a certain range of the root diameter,the maximum root-soil friction increased first and then decreased with the increasing soil moisture,while increased with the rising soil dry density.