摘要
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。
The installation of drainage holes is one of the important practical measures to decrease the seepage pressure and groundwater table in rock and soil masses. Owing to its clear concept and simplicity, the extended seepage tracking method for slot instead of well curtain, which is based on the theory of equivalent discharge, is widely used in the seepage simulation for the well curtain in confined aquifer. The additional seepage tracking in the existing extended seepage tracking method is closely related to the thickness of the aquifer and the depth of the wells, which makes it difficult to be used in the situation containing multilayers and free surface. To remove the limitation of this method, an improved method for seepage problems with drainage holes curtains in multilayered anisotropic mass containing free surface is developed in this paper, in which the formulation of the additional seepage tracking is no longer related to the depth of a drainage hole and the thickness of aquifer. Finite element analyses of several typical drainage holes curtains in the overflow, escape flow and composite flow situations are given by this method. The solutions are compared with the solutions of every drainage hole directly modeled. The results show that the differences between the fluxes by the extended seepage tracking method and those by direct modeling method are very small; and the free surfaces from these two methods are similar. It also shown that the proposed extended seepage tracking method is a simple and effective method to simulate the seepage behaviors of drainage holes curtains.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第1期180-188,共9页
Rock and Soil Mechanics
基金
中央高校基本科研业务费专项资金项目(No.2013BH008)资助项目
中国农业大学教育基金"岩土力学研究创新团队"项目~~
关键词
渗流
排水孔
以沟代孔列
延长渗径法
附加渗径
seepage
drainage hole
slot instead of hole curtain
extended seepage tracking method
additional seepage tracking
