基于FLAC3D的寒旱环境植被根系分布形态对边坡稳定性的影响

随着生态护坡技术的不断发展，植被根系固土护坡作用越来越受到重视。为研究寒旱环境的霸王植被根系分布形态对边坡稳定性影响，同时减少试验成本和挖掘根系对环境的破坏，将根系简化为主根型，通过数值模拟根-土复合体直剪试验，获得与室内根-土复合体直剪试验基本吻合的抗剪强度参数，采用无限边坡理论模型，对不同分布形态根系穿过滑裂面的边坡进行稳定性影响分析。研究发现：不同垂直压力作用下，土体进入塑性剪切阶段时，素土剪切应力均小于根-土复合体；随根截面比增加，土体黏聚力增加幅值大于内摩擦角；当根截面比为0～0.88%时，根系穿过边坡潜在滑裂面时，边坡稳定系数增幅显著，但大于0.88%时，边坡稳定系数增幅较小。因此，在植物固坡工程设计中应找到最优根截面比，以满足寒旱环境边坡的稳定性要求。

Study on the effect of vegetation root distribution morphology on slope stability in cold and arid environment based on FLAC3D

With the continuous development of ecological slope protection technology, more and more attention has been paid to the role of vegetation roots in soil fixation and slope protection. In order to study the influence of root distribution patterns of overgrown vegetation on slope stability in cold and drought environment, reduce test costs and dig root damage to the environment, the root system was simplified as the primary root type. Through numerical simulation of direct shear test of root-soil complex, the shear strength parameters basically consistent with the indoor direct shear test of root-soil complex were obtained. The infinite slope theoretical model was adopted. The stability effects of different distribution forms of root systems passing through the sliding surface of the slope were analyzed. The results show that the shear stress of plain soil is smaller than that of root-soil complex when the soil enters the plastic shear stage under different vertical pressures. With the increase of root section ratio, the increasing amplitude of soil cohesion is larger than the internal friction angle. When the root section ratio is 0.00~0.88% and the root passes through the potential sliding surface of the slope, the slope stability coefficient increases significantly, but when the root section ratio is greater than 0.88%, the slope stability coefficient increases less. Therefore, the optimum root section ratio should be found in plant slope engineering design to meet the stability requirements of the slope in cold and drought environment.