中文摘要：

降雨入渗分析是预测降雨诱发滑坡的关键因素之一。Green-Ampt模型原理简单、使用方便,在浅层滑坡的降雨入渗分析中有很大的应用潜力,但该方法主要适用于初始含水率为均匀分布的情况。基于这一不足,推导了初始含水率为非均匀分布条件下降雨入渗深度和时间的关系,并给出了基于Runge-Kutta原理的数值解法。当初始含水率为均匀分布时,提出的方法可简化为文献中已有的Green-Ampt模型。当初始含水率为非均匀分布时,Richards方程预测所得的孔隙水压力分布图中土体饱和区和未受降雨影响的非饱和区之间存在一个较窄的过渡段,由新模型计算所得的湿润锋穿过这一过渡段,且靠近饱和部区的底部。总体而言,新方法计算所得的孔隙水压力分布与Richards方程求解结果类似。

英文摘要：

Rainfall infiltration analysis is key to the prediction of rainfall-induced slope failure. Due to its simplicity and ease to use, the Green-Ampt model is potentially very useful for rainfall infiltration analysis in prediction of shallow landslides. However, the original Green-Ampt model assumes that the ground is level and that the initial distribution of water content does not vary with depth. In this study, the governing equation for infiltration analysis of sloping surfaces with arbitrary distribution of initial water content is derived. The Runge-Kutta method is used to solve the equation numerically. The modified model can be reduced to the previous Green-Ampt model when the initial water content is uniformly distributed. When the initial water content is not uniform, Richards＇ equation shows that there is a transition zone between the saturated and unsaturated zone which is not affected yet by the rainfall infiltration. The wetting front calculated from the modified method is in this transition zone and is close to the bottom of the saturated zone. Overall, the distribution of pore water pressure predicted from the modified Green-Ampt model is close to that predicted based on Richards＇ function.