【摘要】 多孔介质中毛细吸力作为其重要物性参数,有着重要的工程应用背景。本文结合Gardner模型的土水特征曲线和Micro-CT(Micro computerized tomography)断层扫描仪获取的多孔介质的结构形态参数,根据吸力和饱和度的拟合关系,建立了一维非饱和毛细上升模型。同时,采用有限差分方法对多孔介质非饱和毛细水上升模型进行非稳态求解,获取不同时刻湿度场和毛细吸力的分布情况,并给出了一种量化多孔介质毛细上升过程的理论方法。为验证该方法的有效性,本文在室内以窄筛分洗砂作为研究对象,通过室内试验测定其毛细吸渗上升过程及稳定时的湿度分布。结果证实,模拟结果和实测结果整体上具有较高的吻合性。本文提出的多孔介质毛细上升的预测方法具有可行性,可用于预测砂土的毛细水上升高度和湿度场的分布状态。更多还原

【Abstract】 Capillary suction is one of the vital physical parameters to porous media and has been widely concerned in engineering practice.This paper combines the Gardner soil-water characteristic curve model and the structure parameters obtained by Micro-CT tomography at first.The unsaturated capillary rise model and a specific quantification for capillary rise in the porous media are then developed using the fitting relationship between suction and saturation and the finite difference method.Furthermore,laboratory experiments are carried out to confirm the availability of the model,where the narrow sub-washed sand is chosen as object.Parameters of the capillary rise process and the stable distribution of moisture are measured actually.Results indicate that a good agreement is presented between test and theoretical values.The proposed theory is feasible to predict the capillary rise and the moisture distribution of sand.更多还原