竹林网络化鞭根系统的固土护坡力学机制及其计算机模拟分析研究

The ability of vegetation to stabilize and strengthen soil is now well recognized, and this knowledge has been applied to reinforce slopes. The vegetation roots play an important role in the process. Now, most researchers focus on the root-soil mechanics of shrubs, arbors and grasses. However, only a few studies have evaluated the effect on slope stability of the bamboo's rhizome-root systems that are characterized by the complex network. We will concentrate on the root-soil mechanics and interactions for this kind of bamboo's rhizome-root systems. The ground-penetrating radar and image analysis are used to obtain the geometry parameters of the rhizome-root system. The shear stress is used to obtain the influence of root system morphology and architectural traits on soil shear resistance. At last, computer simulation and finite element analysis are used to discuss the mechanics of the rhizome-root system. The aim of this study would be to: (1) Understanding the fundamental evolution mechanisms of bamboo's rhizome-root system and the mechanical properties of the root-soil composite system. (2) Quantifying the impact of different network configurations of bamboo's rhizome-root system in slope stability, and especially establishing the new mechanism and analysis model for the large scale rhizome-root system on soil erosion control. This project will greatly advance and deepen the mechanical theory research of bamboo's rhizome-root system. Also, this information will be valuable for providing a more comprehensive view to understand the whole effect of soil erosion control and slop stability.

长期的科学研究与实践证明，植被一直是防治水土流失最积极有效的因素，根系在该过程中扮演着重要角色。目前，针对植物根系固土护坡力学机制的研究，主要集中在灌木、乔木和草本植物；而对于网络化构型特征明显的竹林鞭根系统的固土护坡力学作用机制研究较少。本项目以网络化构型特征明显的竹林鞭根系统为研究对象，利用探地雷达无损探测、剪切-应力测试等技术手段，获得竹林鞭根系统几何构型参数与鞭根土复合层内部力学特性。并通过计算机根系构型模拟与有限元分析，试图：1）探明竹林鞭根系统网络化构型的发展演化规律和鞭根土复合层内部力学传递机制；2）模拟分析不同网络化构型对坡面固土护坡的影响，特别研究竹林鞭根系统网络化规模效应对固土护坡效果的影响机制。本项目的实施可完善、加深和提升根系固土护坡机制的理论研究；为理解具有网络化构型的竹林鞭根系统对固土护坡的影响提供新的、全面的认识。

竹林鞭根的网络化构型对于固土护坡具有重要意义。如何实现竹林地下网络化鞭根构型的无损获取是相关科学研究的基础。本项目发展了植物根系多尺度无损观测技术与相关数据分析方法。具体如下：本项目利用计算机视觉与激光跟踪双模态运动目标协同定位技术，实现了对地观测天线空间位姿的高精度跟踪和系统运行的鲁棒性，进而通过对任意空间位置单道电磁波谱的三维空间定位，获取了竹林地下鞭根的三维高精度电磁波谱图。项目通过设计根系生长接引装置，实现根系自动生长进入所设计的独立区域。从而实现同一植株的不同根系在独立区域的全生命周期无损监测。针对计算机根系构型模拟与有限元分析，本项目发展了低冗余高可靠性存储方法和基于内存的分布式协同分析方法，从而提高了数据的查询效率与计算速度，为根系相关图像与数据的处理奠定了计算基础。