植物根系抗拉力学性能研究进展

根系是植物固土的基本单元,根系力学性能研究是植物根系固土研究的基础。植物护坡工程中,植物根系通过发挥抗剪和抗拉作用提高边坡稳定性。根系抗拉能力是增强边坡稳定性最重要的因素之一,根系抗拉力学性能研究具有重要意义。在分析国内外多种植物根系抗拉力学性能研究的基础上,总结了这些植物根系抗拉力学特性的研究现状,分析比较了植物根系抗拉力学性能研究试验的方法和多种影响因素与植物根系抗拉性能的关系,得出如下结论:①目前尚未形成标准的根系抗拉试验,根系抗拉性能试验研究的方法和设备有待科学规范;②根系直径与抗拉力和抗拉强度关系研究已经形成共识,即根系直径越大,抗拉力越大,抗拉强度越小;③根系抗拉强度随根系采伐时间的推移而降低;④根系长度、含水量、加载速率、根系内部化学成分和微观结构等对抗拉力和抗拉强度的影响研究较少,尚未形成统一结论,还需要加强研究。最后,探讨了植物根系抗拉力学性能研究存在的问题和趋势,认为夹具的改进、根系形态解剖结构研究、根系疲劳破坏研究应成为今后研究的重点。

Research progress on the tensile mechanical properties of plant roots

The root system is the basic unit of soil reinforcement by plants, and the research on the tensile mechanical properties of root system lays the foundation of studies on soil reinforcing effects of plant roots. In slope protection engineering which employs plants, the root system improves the stability of the slope through its shear resistance and tensile resistance. Researches have shown evidence that the tensile strength of root system is one of the most important determinants of enhancing slope stability. Therefore, research on the mechanical properties of root tensile strength is of great significance. Based on the analysis of various studies about the properties of tensile strength of root system by both Chinese and international researchers, this paper not only gives a summary of the current status of these studies but also analyzes and compares the experimental methods employed in these studies, and examines the relationship between various determinants and the tensile performance of root system of plants. Conclusions of this paper are as follows:(1)There has not formed a standardized tensile test for root system yet, and the scientific specifications for methods and devices used in the experimental study on the tensile properties of root system should be implemented; (2) The consensus among studies on the relationship between the diameter of root system and its tensile resistance and tensile strength is that the tensile resistance is in a positive correlation with the diameter of the root system while the tensile strength is in a negative correlation with it; (3)The tensile strength of the root system declines with the passage of time since the plant is uprooted; (4) There have no enough researches on the impacts of length, water content, loading rate, chemical components and micro-structure of root system on its tensile resistance and tensile strength, no consensus conclusion has yet been reached and therefore further researches are needed. Finally, this paper explores the problems and trends of researches on the tensile mechanical properties of root system of plants, and argues that the emphasis of future research will be on the improvement of clamps, structural study on the morphological anatomy of root system and the study on the fatigue failure of root system.