强降雨条件下非饱和粉土雨水渗透规律研究

Study on the rainwater infiltration law of unsaturated silt under heavy rain

由雨水渗透规律计算得到的雨水渗透体积是判断非饱和土粉土强度受降雨扰动的主要参数。提供一种强降雨条件下非饱和粉土雨水渗透规律的计算方法,可以根据降雨条件与土体性质预测非饱和粉土在降雨渗透过程中雨水渗透率随时间的变化规律。该方法通过扩展已有非饱和土渗透模型建立降雨渗透计算模型。在经典Green-Ampt模型基础上,根据土体含水量的不同和在降雨过程中出现顺序,依次将土体进行分层。采用毛细渗透公式与达西定律对降雨渗透过程分阶段进行计算,得到降雨渗透过程中雨水渗透率随时间的变化规律。与实验实测数据的对比表明,理论计算值与实验实测数据基本吻合,能较好的预测雨水渗透率变化规律。

The rainwater infiltration volume calculated from the law of rainwater infiltration is the main parameter to judge the strength of unsaturated soil silt disturbed by rainfall. This article provided a method for calculating the rainwater permeability of unsaturated silty soil under heavy rainfall conditions. Based on the rainfall conditions and soil properties, it was possible to predict the regularity of rainwater permeability of unsaturated silty soil during rainfall infiltration. This method established a rainfall infiltration calculation model by extending the existing unsaturated soil infiltration model. Based on the classic Green-Ampt model, the soil layers were divided in turn according to the different soil moisture content and the order in which they occur during rainfall. Capillary infiltration formula and Darcy’s law were used to calculate the rainfall infiltration process in stages, and the change pattern of rainwater permeability with time during the rainfall infiltration process was obtained. The comparison with the experimental data shows that the theoretical calculation values are basically consistent with the experimental data, which can better predict the change law of rainwater permeability.