红粘土土质边坡乔木根-土复合体剪切试验

摘要

In order to study the strengthening effects of root system of arbor and understand the mechanism from root morphology,this article selected 4 arbor species,which is common in tropical rain forest,to do the in-situ shear test and statistical analysis of root system,and access to the root and soil under different depth of complex relationship between shear stress and displacement curve.Through laboratory direct shear tests we got shear strength of undisturbed soil,calculate the different root and soil complex soil shear strength growth rate by comparing their distribution.Finally it was concluded that under the condition of the scene in situ,Terminalia Mantaly composite soil shear strength of the growth rate was the biggest,followed by Chinese Bischopwood and Flamboyanttree,Khaya Senegalensis root is the worst.There was an optimal root soil area ratio,and it enables the root to stabilize their own to improve the soil shear strength.%为研究雨林乔木类树种的根系存在对红粘土土质边坡的加固效果,并从根系形态、几何特征方面研究其加固机理,选取海南热带雨林地区常见的四类直根系乔木树种进行现场大型剪切试验和根系实地统计,获取不同深度下根-土复合体的剪应力与位移关系曲线,并取相应的原状土进行室内直剪试验,将现场剪切试验条件下测得的根-土复合体抗剪强度与室内素土抗剪强度进行比对,计算出不同根-土复合体土体抗剪强度增长率,最终得出在现场原位条件下,四类树种根系中小叶榄仁根-土复合体抗剪强度的增长率最大,其次是重阳木根系和凤凰木根系,非洲楝根系最差;对于四类树种来说都存在一个最优根土面积比,使得根系能最大限度地发挥自身提高土体抗剪强度的作用.