【作者】 王玉林；

【导师】 谢康和；

【作者基本信息】 浙江大学 ， 岩土工程， 2011， 博士

【摘要】 承压地下水开采目前已成为影响地下水运动变化最主要的因素之一,也是引发地面沉降和沉陷等环境地质灾害的主要原因。承压地下水开采模型及其渗流理论历来在预测和控制地下水开采引发的环境地质灾害中发挥着重要的作用。本文在前人关于地下水抽水井流模型和相关渗流理论研究的基础上,针对现有模型和理论中存在的不足,以及根据实际需要,研究了新的抽水井设置方式和抽水-灌水模式下承压含水层地下水渗流问题,建立了特定地质水文条件下开采地下水的数学模型并进行了求解和分析；对受潮浪和径流补给影响的滨海承压含水层地下水开采问题以及井周非均匀、各向异性表皮层和各向异性、层状承压含水层抽水产生的渗流等问题建立了新的数学模型并进行求解和较详细的分析。主要工作和创新成果包括：1.为减小抽水产生的承压含水层水头降落漏斗深度和范围,对传统开采水井作了改进,设计了集抽、灌水功能于一体的抽一灌同轴井。针对同步或非同步循环抽水和灌水产生的承压含水层井流建立相应的数学模型,给出了相应的解析解,该解既可以退化到已有的考虑越流的定流量完整井解析解和定流量非完整井解析解,也可退化为Theis (1935)解。并通过计算分析阐明了循环抽水和灌水模式下承压水头降等变化规律。2.针对潮浪影响、越流补给和径流补给共同作用下的滨海承压含水层地下水开采问题建立了数学模型,利用双重傅立叶变换得到承压地下水非稳态井流的解析解,现有相关解均为其特例。基于该解详细分析了潮浪和径流等对滨海承压含水层抽水井流的影响以及多因素共同作用下承压地下水的发展变化规律。3.对末穿透承压含水层覆盖层的承压泉水井或基坑坑底降水井抽取承压含水层产生的地下水渗流问题分别建立了三种侧向边界条件下的抽水井流模型,给出了不同条件下的水头降表达式；对比分析了三种边界条件下承压含水层水头降随时间发展规律以及沿厚度和径向分布规律的差异；详细分析了三种边界条件下的水头降随时间发展速度和空间分布规律,以及越流补给、各向异性、井底渗流面大小、承压含水层厚度和宽度等对水头降速率和幅度的影响。4.考虑表皮效应随机分布和各向异性以及承压含水层的层状结构和各向异性,建立了径向单层和径向双层两种情形的承压井流数学模型,通过矩阵理论和Laplace变换方法,分别求得了两种情形下的解。所求解能够退化到简单表皮效应条件下的现有解。利用所求解全面分析了非均匀、非等厚和各向异性表皮层对层状、各向异性承压含水层中水头降和抽水流量变化规律以及正、负表皮效应对承压含水层水头降和抽水量的差异。更多还原

【Abstract】 Groundwater exploitation has become nowadays one of the main factor that change the movement way of groundwater and also the main reason causes environmental and geologic hazard such as subsidence and sink of ground. Studies of the subject involved in this dissertation are important, because it provides a tool for knowing and mastering the information of groundwater change, and test methods of geohydraulic parameters. What’s more, it plays important role in discovering some mechanism for subsidence, sink and fissure of ground and other environment geology disaster due to pumping groundwater.Based on the exsiting achievement about the models for well flow of groundwater and related theoretical solutions, and on account of some defect in the models and theory for groundwater exploitation, this dissertation has made some development and improvement for the models and theories of well flow due to confined water exploitation. The main original work and innovative achievements are as follows:1. To reduce the amplitude and affected area of drawdown of hydraulic head in confined aquifer caused by pumping, a new vertical well is designed, which contains double screens. With such a kind of well, a 3D flow model for confined aquifer, subjected to pumping and injection in synchronou or nonsynchronous way, is developed. Then, by application of Hankel transformation and Laplace transformation, the corresponding analytical solution is obtained, which is more general and can reduces to the solutions for full penetrating well and partial penetrating well in leaky confined aquifer and also to Theis’s (1935) solution. The solution is used to analyze interplay of flow casused by pumping and injection and the change of hydraulic head in the confined.2. When pumping in the coastal leaky confined aquifer with runoff toward ocean, well flow may be influenced by not only the tide, but also the runoff. In order to study the comprehensive effect of groundwater flow under several factors, a mathematical model is formulated, and then by double Fourier transformation, the analytical solution is presented, which is consistent with some available solutions under a simpler condition. Based on the present solution, the effect of tide, runoff and other factors on well flow and hydraulic head in coastal confined aquifer is studied.3. Some pumping wells located above the confined aquifer without penetrating the covering layer of confined aquifer, and the water infiltrating from confined aquifer through the well bottom is continuously pumped off, which may lead to drawdown of hydraulic head in confined aquifer. For sucn a special problem, a mathematical model with three different lateral boundary conditions is developed for groundwater flow in the confined aquifer, and three ananlytical solutions are presented. The development and distribution of drawdown of hydraulic head under three lateral boundary conditons is compared. And the responses of hydraulic head under three lateral boundary conitions to different factors, such as leakage, anisotropy, the area of well bottom, thickness and width etc, are analyzed in detail.4. With consideration of radomly vertical distribution and antisotropicity of wellbore skin, and layered formation and antisotropicity of the the confined aquifer, two mathematical models for groundwater flow are developed. One model is neglected of skin storage and the other takes consideration of skin storage. And by finite diffence method, the semianalytical solutions for two models are obtained. The present solutions can reduce to some previous available solutions with simple skin conditions.The new solutions can be ued to analyze the effect of nonuniform and anisotropic wellbore skin on the drawdown and flow rate in layer-formulated and anisotropic confined aquifer and the different effects of negative and positive skin on drawdown and flow rate.更多还原