根土复合体力学效应及其模型构建研究进展与展望

目的] 为探究根土复合体的力学效应机理及模型方法应用。方法] 采用文献分析和对比分析法,归纳分析根土复合体概念和内涵、根土复合体力学效应及力学模型原理、优缺点以及适用范围。结果] (1)根土复合体是根系与土体之间力学耦合效应的复合整体,根系在土体中交叉缠绕,起到加固作用;(2)根系与土体力学关系实质上是根土复合体土力、水力和复合力学特性作用的结果,土力特性、水力特性分别侧重研究根系对土体的影响和土中水分对土体和根系的影响,复合力学特性侧重于根土复合体自身特性对植物根系特征以及结构的直接影响,从而通过三者作用使根系与土体的力学关系处于动态平衡之中;(3)根土复合体复合力学模型研究较土力和水力学模型略少,土力学和水力学模型都是根据量化参数,通过参数间对比来衡量固土效果,但复合力学特性同时涉及土力特性和水力特性,考虑全面,应是未来研究的重点方向。结论] 未来在开展冻融循环、干湿交替、干热循环对不同地区根系与土体相互作用的影响、多类型植物混种抗剪强度、化学作用和微生物作用对土水特性影响机理及复合模型构建等方面有待深入研究。研究结果可为生态脆弱区植被恢复、水土保持和可持续发展等提供重要的理论价值和工程借鉴意义。

Research Progress and Prospect of Mechanical Effects and Model Construction of Root-soil Complex

Objective] In order to investigate the mechanism of mechanical effect of root-soil complex and the application of modeling method. Methods] The concept and connotation of root-soil complex, the principle of mechanical effect and mechanical model of root-soil complex, advantages and disadvantages as well as the scope of application were summarized and analyzed by using literature analysis method and comparative analysis method. Results] (1) The root-soil complex was a composite whole of mechanical coupling effect between root system and soil body, and the root system was intertwined in soil playing a reinforced role. (2) The mechanical relationship between root system and soil body was essentially the result of soil mechanical, hydraulic and composite mechanical properties of root-soil complex. The soil mechanical and hydraulic properties focused on the influence of roots on the soil and the influence of water on the soil and root system respectively, and the composite mechanical properties focused on the direct influence of soil properties on the properties and structure of plant roots, so that the mechanical relationship between roots and soil was in a dynamic balance through the three. (3) The study of the composite mechanical model of the root-soil complex was slightly less than that of the soil mechanical and hydraulic model, which were based on quantitative parameters and measure the soil consolidation effect by comparing parameters. However, the composite mechanical properties involves both soil and hydraulic properties, which was a comprehensive consideration and should be the key research direction in the future. Conclusion] In-depth research was needed in the future to investigate the effects of freeze-thaw cycle, dry-wet alternation and dry-hot cycle on root and soil interaction in different regions, the shear strength of multi-type plant mixtures, the influence mechanism of chemical and microbial effects on soil-water propertiess and the construction of composite models need to be further studied. This study can provide important theoretical value and engineering reference for vegetation restoration, soil and water conservation and sustainable development in ecologically fragile areas.