基于非饱和渗流原理的粉土路基水份分布规律研究

Distribution of Silty Soil Subgrade Moisture Content Based on Unsaturated Seepage Principle

为了研究粉土路基内部含水率分布规律,建立了基于非饱和渗流原理的有限元数值仿真模型,研究了地下水位、降雨、蒸发作用等因素对路基材料含水率的影响作用,采用稳态及瞬态渗流计算,确定了粉土路基及边坡材料含水率变化规律;通过埋设频域反射仪湿度传感器对路基含水率年变化规律进行了实测,验证了理论分析模型的可靠性。研究结果表明:路基的含水率均随地下水位的升高呈指数形式上升,持续的降雨蒸发作用对路基边坡影响深度范围是0.2～0.3 m;预估含水率与实测值基本一致,预估误差最小为3.9%,最大为8.9%,说明基于非饱和渗流原理的有限元模型对路基含水率的预估具有较高的精度。

In order to study the distribution of silty soil subgrade moisture content, a finite element numerical simulation model based on unsaturated seepage principle was established, and the influence of water table, rainfall, evaporation and other factors on the moisture content of subgrade material was analyzed. The variation of moisture contents in silty soil subgrade material and slope material were determined by steady- state and transient seepage calculations. The annual variation of subgrade moisture content was measured by laying frequency domain reflectometry humidity sensor to verify the reliability of the theoretical analysis model. The results show that （1） subgrade moisture content increases exponentially with water table, continuous evaporation of rainfall influences the subgrade slope in the depth of 0. 2 -0. 3 m; （2） the estimated moisture content is consistent with the measured values, the smallest estimated error is 3.9%, the maximum is 8.9%, so that the finite element model based on unsaturated seepage principle has high accuracy for estimating subgrade moisture content.