基于试验与模型的根系增强抗剪强度分析  

Analysis of root system enhancing shear strength based on experiment and model

作　　者：朱锦奇[1] 王云琦[1] 王玉杰[1] 张会兰[1] 李云鹏[1] 刘勇[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《岩土力学》2014年第2期449-458,共10页Rock and Soil Mechanics

基　　金：中央高校基本科研业务费专项资金资助"水土保持工程机制及效应研究"(No.TD2011-01);国家自然科学基金"基于分形理论的三峡库区林地土壤结构特征与土壤侵蚀关系"(No.30671661)

摘　　要：在总结近代学者对植物根系固土作用机制研究的基础上,采用大盒直剪试验与物理模型,对重庆缙云山地区6种常见植物:马尾松、香樟、广东山胡椒、四川大头茶、白毛新木姜子、四川山矾根系的增强抗剪强度进行对比。通过自制的大盒直剪仪对植物实际固土效果进行了测定,该大直剪仪具有简单、经济、易行等特点。通过对多种植物根系进行抗拉试验和根土复合体受力分析,确定了植物根系的抗拉强度与植物根面积比率。利用Wu模型对6种植物的根系固土效能进行模型计算。结果表明,不同的植物根系类型对增强抗剪强度值的影响非常显著。在重庆缙云山地区的土壤质地情况下,Wu的根土复合体模型高估了根系增强土壤的抗剪强度约为90%。基于该结论,为使Wu模型计算的根系固土强度值较为准确,修订Wu模型中的k值为0.63。Based on present studies of the enhancement of root system on soil shear strength, this study investigated root reinforcement effect of six common plants, i.e. Pinusmassoniana Lamb, Cinnamomumcamphora （L.）, Linderakwangtungensis （Liou） Allen, Gordoniaacuminata Presland Neolitseaaurata var. glauca, within acidic zheltozem area of Chongqing Jinyun mountain, by direct shear test and numerical modeling. This study was firstly implemented by a self-made large box direct shear apparatus, characterized by simple, economic, effective and reliable. Moreover, the root system reinforcement effect was quantified by the equipment. Besides, the root area ratio was calculated and root tensile strength was derived by laboratory test experiment. Further, the well-known Wu root-soil composite model was triggered with the same boundary condition as indoor experiment;and then the model calculations were compared with the experimental measurements. The results show that the above six types of plant roots notably enhance the soil shear strength, but with different levels. It is also demonstrated that Wu root-soil composite model overestimated soil shear strength by 90% compared with the large box shear test. In this manner, we revised the k value as 0.63 for soil textures in Jinyun mountain of Chongqing.

关 键 词：根土复合体 根面积比率 抗剪切强度 

分 类 号：TU411.7[建筑科学—岩土工程]