【作者】 曹彭强；

【导师】 陶月赞；

【作者基本信息】 合肥工业大学 ， 水文学及水资源， 2007， 硕士

【摘要】 河渠渗流、土坝渗流、边坡渗流等皆属于有自由面的无压渗流问题。这类问题的自由面位置是待求的，事先未知，如何简捷、有效地确定自由面的位置历来都是无压渗流场分析的关键。自由面渗流分析方法很多，归纳起来主要有解析法、数值法和模拟法等三大类；在自由面渗流规律研究过程中，往往依赖解析法。关于自由面渗流规律的研究，现有文献给出的模型，其初始自由面都是稳态的；以河渠一半无限含水层中的潜水渗流模型为例，初始自由面不仅是稳态的、而且往往是水平的，这既不符合大多数实际情况，也不具有普遍性。本文以河渠控制下的半无限潜水含水层中的潜水渗流模型为例，构造初始面非稳定条件下的一维潜水非稳定渗流模型；利用Boussinesq第一线性化方法，通过Laplace变换，再结合迭加原理，导出模型的解析解；并以其为基础，讨论模型中参数的计算方法、研究非稳定初始面对自由渗流的影响规律。研究表明，文中建立的潜水非稳定渗流模型合理，所给出解析解考虑了非稳定初始面因素，计算的自由面位置比原潜水渗流模型的解更接近观测值；规律研究显示非稳定初始面对自由渗流的影响与导压系数（α）、时间因子（T）和时间（t）成反比，与河渠原水位和最初初始面水位之差（△H₁）及距河渠距离（X）成正比。更多还原

【Abstract】 The seepage of waterway, soil-dam and side-slope are belongs to not press groundwater flow problems with free surfaces. The free surfaces’ position is unknown and requested. How to calculate the free surfaces’ position briefly and effectively is a sticking point. The analysis methods of flow with free surface can divide into three major type: analytical method, mathematical method and simulation method. The analytical method used currently in free seepage regulation researching. Presently research of free surface flow regulation always use steady beginning free surface. Take the potential flow model of waterway- semi-infinity porous medium for example, all now study are all use steady beginning free surface, and is usually horizontal. This is obviously not agreed with actual circumstances, also not have the theories meaning of catholicity.Take the potential flow model of waterway- semi- infinity porous medium for example, the one-dimensional seepage model of a infinite aquifer have not perpendicularity seepage with unsteady free surface is described. Based on the first linearized Boussnesq equation, the analytical solution of the model mentioned above can be obtained by Laplace transform combined with the principle of superposition. Base on the analytical solution, the account method of parameters in the model and the affect disciplinary of unsteady free surface are analyzed.The result shows that the parameter-computation method proposed by the paper is reasonable. Comparing with the original solution, the new analytical solution subject to unsteady beginning-surface is more accurately approaches to the observation value. Regulation research show that the affection of unsteady beginning-surface in inverse proportion to press transmit coefficient （α）、time gene（T） and the time（t）,but in direct proportion to the water level difference（△H₁） between the waterway and prime beginning-surface and the distance to waterway（x）.更多还原