考虑潜蚀影响的降雨入渗边坡稳定性分析

在降雨入渗作用下土坡内细颗粒会随渗流发生运移产生潜蚀作用。通过联立颗粒运移方程与非饱和土渗流方程,结合非饱和土水力特性方程和土体潜蚀本构关系,建立了渗流潜蚀耦合的边坡稳定性分析模型。采用有限元方法模拟了降雨入渗作用下潜蚀和入渗的相互作用,分析了初始饱和渗透系数、进气值参数对入渗和边坡稳定性的影响。结果表明：潜蚀主要发生在湿润锋范围内浅层土体,潜蚀加速了湿润锋下行速度,进一步降低边坡稳定性;饱和渗透系数、进气值是影响渗流潜蚀作用的主要因素;当降雨入渗强度大于饱和渗透系数时,饱和渗透系数越大,潜蚀对入渗和边坡稳定性的影响越显著;进气值越小,潜蚀作用对入渗和边坡稳定性的影响越显著。

Slope stability under rainfall infiltration considering internal erosion

Internal erosion and transport of fine particles may be induced by the seepage and infiltration of rainwater into a slope. In this study, the interaction between the transport of fine particles and the infiltration in a soil slope is investigated. A slope stability model considering coupling of seepage and internal erosion is established. The effects of the initial saturated permeability and air-entry value parameter on the slope stability and seepage are studied. The results of an illustrative example show that the internal erosion occurs mainly in the zone within the wetting front, which accelerates the advance of the wetting front and the slope stability is reduced consequently. The initial saturated permeability and air-entry value parameter are the main factors to affect the internal erosion in the slope. When the saturated coefficient of permeability is greater, the effect of the internal erosion on the infiltration and slope stability becomes more significant as long as the rainfall flux is equal or greater than the saturated coefficient of permeability. When the air-entry value of the soil is greater, the influence of the internal erosion on the infiltration and slope stability becomes less significant.