论文部分内容阅读
排水孔是降低岩土体中地下水位和减小渗透压力的重要设施。因排水孔孔径小、排列密集,研究排水孔列的简化模拟方法对减小渗流数值计算规模,提高计算效率十分必要。基于流量等效原理的以沟代井列的延长渗径法,因其概念清晰、实现简便,在承压含水层井列的渗流场模拟中应用广泛。现有以沟代井列的延长渗径法中附加渗径计算公式与井深和含水层厚度息息相关,使得该方法应用于多层和有自由面的问题困难重重。针对现有延长渗径法的局限性,提出适用于有自由面的各向异性多种介质中排水孔列渗流问题的延长渗径法,附加渗径长度的确定不再受到孔深和含水层厚度的影响。采用该方法对几个典型的溢流型、逸出型和复合型排水孔列进行渗流场有限元分析,并与排水孔直接模拟的结果进行对比。结果表明,延长渗径法得到的排水孔的流量与排水孔直接模拟法的流量相差很小,且两种方法获得的自由面基本吻合。因此,提出的延长渗径法是模拟排水孔列渗流行为的简单而有效的方法。
Drainage hole is to reduce the groundwater level in the rock and soil and reduce the infiltration pressure of the important facilities. Due to the small pore size and dense arrangement of drainage holes, it is necessary to study the simplified simulation method of drainage holes to reduce the numerical calculation of seepage flow and improve the calculation efficiency. Because of its clear concept and easy realization, the extended diameter-gage method based on flow equivalent principle is widely used in the simulation of seepage field in well-strata of confined aquifers. The existing formula for calculating the additional borehole diameter in the extended gob-diameter method with the Gupo-Jing column is closely related to the depth of the well and the thickness of the aquifer, making the method difficult to apply to the problem of multiple layers and free surfaces. Aiming at the limitation of the existing extension of the diameter of percolation method, the extended percolation method which is suitable for the seepage of the perforation columns in anisotropic medium with free surface is proposed. The determination of the additional percolation length is not limited by the depth of hole and aquifer The effect of thickness. By using this method, finite element analysis of seepage field of several typical overflow, escape and composite drainage hole columns is made and compared with the results of direct simulation of drainage holes. The results show that there is a small difference between the flow rate of the drainage hole obtained by the extension of the diameter-percolation method and the direct simulation method of the drainage hole, and the free surface obtained by the two methods basically agrees. Therefore, the proposed extension method is a simple and effective method to simulate seepage behavior of drainage holes.