大理石平板裂隙水运移实验与模拟研究

Experimental and simulated study of water flow and transport in a single fracture of marble parallel plates

为了揭示单个裂隙中水流和溶质运移的规律,该文选取大理石平板作为实验介质,开展了平板裂隙水运移实验,分析了水力梯度和水流速度之间的关系,研究了溶质运移规律;利用连续时间随机步长(CTRW)软件包中的截断幂函数(TPL)模型对溶质浓度穿透曲线进行了模拟,并与传统的对流-弥散方程(ADE)模拟结果进行了对比。结果表明:实验条件下,大理石平板裂隙水流为非达西流,利用Forchheimer方程可以更好地模拟;大理石平板裂隙内溶质运移为no-Fickian运移,表现出明显的拖尾现象;在不同流速条件下模拟溶质穿透曲线时,利用TPL模型拟合结果明显优于ADE模型。

In order to reveal the laws of the flow and solute transport in a single fracture, flow and transport tests have been conducted in plate fractures. Marble parallel plates have been used as experimental media in this study. The relationships between the flow velocity and the hydraulic gradient were analyzed and the laws of flow and solute transport were studied. The breakthrough curves of solute were simulated using the truncation power-law function （TPL） model in the package of the continuous time random walk （CTRW）, comparing with the simulated results using traditional advection-dispersion equation （ADE）. The results indicated that the laws of flow are non-darcian flow in the experimental conditions, which can be better simulated using the equation of Forchheimer; the solute transport presents no-Fickian phenomena and shows obvious trailing phenomena; the fitting results using of TPL model are significantly better than ADE fitting results trader different flow velocity conditions.