降雨条件下草本植物根系对残积土边坡渗流稳定性的影响

为研究紫穗槐和胡枝子两种植被根系对残积土边坡的渗流稳定性影响,本实验研究设计采用数值模拟的方法进行研究,以Geo-studio软件为平台,计算分析不同降雨强度作用下,裸坡与指数形根系和均布形根系对边坡渗流及稳定性的影响规律,计算的内容包括孔隙水压力、饱和度和安全系数。研究结果表明：植被边坡的孔隙水压力的上升速度大于裸坡,指数形根系边坡的敏感性高于均布形根系边坡;植被边坡比裸坡易达到饱和,指数形根系边坡对饱和度的变化同样具有较高的敏感性,饱和度变化幅度与降雨强度呈负相关的关系;对残积土边坡稳定性影响效果,指数形根系对边坡稳定性表现得更有利,降雨强度较小时均布形根系提高作用稳定,降雨强度增大时其安全系数向裸坡靠拢,而指数形根系在四种降雨强度下对边坡仍可稳定发挥提高作用,且安全系数一直位于均布形根系之上,对提高残积土边坡稳定性的积极性更高。

INFLUENCE OF HERBACEOUS ROOTS ON SEEPAGE STABILITY OF RESIDUAL SOIL SLOPE UNDER RAINFALL CONDITION

In order to study the influence of roots of Amorpha fruticosa and Lespedeza bicolor on the seepage stability of residual soil slope, numerical simulation method is adopted in this paper. Geo-studio software is used to calculate and analyze the influence of bare slope, exponential roots and uniform roots on seepage and stability of slope under different rainfall intensity. The calculation contents include pore water pressure, saturation and safety coefficient. Vegetation slope is easier to reach saturation than bare slope, exponential root slope is also more sensitive to the change of saturation, and the variation range of saturation is negatively correlated with rainfall intensity. Exponential root system is more beneficial to slope stability, uniform root system can improve slope stability when rainfall intensity is low, and its safety coefficient approaches bare slope when rainfall intensity increases, while exponential root system can still improve slope stability under four rainfall intensities, and safety coefficient is always above uniform root system, so it is more active to improve slope stability.