【作者】 黄峰；

【导师】 王成彪； 王贵和；

【作者基本信息】 中国地质大学（北京） ， 地质工程， 2014， 博士

【摘要】 本文对真空管井降水法引起的地下水真空渗流场的几个主要方面进行了研究,研究方法和主要结果如下：开展了现场实验研究。依托北京地铁14号线工程,开展了真空管井降水的现场实验,对出水量、真空度在水平和深度方向的传递、孔隙水压力以及真空沉降等方面进行了监测,得到了各项指标的变化规律。进行了真空度分布规律研究。在气体运动符合达西定律的前提下,对气体的平面渗流模型和Paul C.Johnson模型进行了分析,得到了井径、井室压力和影响半径等对真空度传递规律的影响。建立了饱和土孔隙水真空渗流场模型。将土体中气体的渗流规律与Dupuit等经典的地下水渗流理论相结合,得到了真空潜水完整井、真空承压水完整井以及真空潜水-承压水井作用下的出水量、水位和水头的分布、水力梯度的变化规律和解析解。为了验证理论分析的正确性,开展了室内抽水实验和数值模拟对理论分析模型进行了验证。对非饱和土孔隙水真空渗流进行了研究。通过分析孔隙水受力情况,得出了重力排水的极限条件；通过分析非饱和土孔隙水的渗流条件,分析了气体补充量对孔隙水排出的作用机制,并通过实验进行了验证；通过对非饱和土土水特征曲线的研究,提出了将进气值作为真空渗流场影响半径的观点：运用有限差分法,对非饱和土孔隙水一维水平真空渗流模型进行了求解。建立了真空条件下的沉降模型。基于真空度传递规律和水位分布模型,讨论了真空作用下仅考虑水位下降情况的沉降计算；建立了真空条件下的Imai模型、Chai J C模型、弹性力学模型和饱和土稳定渗流有效应力模型。进行了真空管井降水的沉降预测。运用回归分析法、灰色理论模型GM(1,1)法和BP神经网络法对真空降水现场实验的沉降数据进行了预测分析。对层间滞水真空渗流规律和降水方法进行了探讨。提出了层间滞水分布的3种形式：水平分布、凹陷分布和倾斜分布。提出了隔水层倾斜分布时真空井“爬坡”运行的降水施工方法。更多还原

【Abstract】 This dissertation made studies on the major aspects of the vacuum seepage field, and the research methods and results are as follows:A field test was made based on Beijing Subway Line14project, during which several aspects of vacuum tube well dewatering including water discharge, the transfer of vacuum degree both in horizontal and vertical directions, pore water pressure and vacuum settlement were monitored to get the changing law of various indicators.The distribution law of vacuum degree was studied. Under the condition that Darcy’s law is applicable to gas seepage, the plane seepage model and Paul C. Johnson model were analyzed to understand the effects of well diameter, well chamber pressure and influence radius on the transfer law of vacuum degree.The vacuum seepage model of pore water in saturated soil was set up. Through studies combining the seepage law of gas in soil and classic groundwater seepage theories such as Dupuit theory, the changing law of water discharge, water level, water head distribution and hydraulic gradient under conditions of fully penetrating well in phreatic aquifer, fully penetrating well in confined aquifer as well as fully penetrating well in phreatic-confined aquifer was obtained and the analytical solutions were deduced further. Meanwhile, laboratory pumping experiment and numerical simulations by Modflow Software were conducted to verify the correctness of the theoretical analysis.The vacuum seepage of pore water in unsaturated soil was researched with the following results:deriving the limit conditions of gravity drainage based on analysis of the stress state of pore water; working out the influencing mechanism of gas supplement on pore water discharge based on analysis of seepage conditions of pore water in unsaturated soil and verifying the mechanism by experiment; proposing the view that takes the air entry value as the influence radius of vacuum seepage field; and making solutions of the one-dimensional horizontal vacuum seepage model of pore water in unsaturated soil using Finite Difference Method.The settlement model under vacuum seepage condition was set up. According to the transfer law of vacuum degree and water level distribution model under vacuum field, settlement calculations under vacuum were discussed considering only water declining condition. Furthermore, several models under vacuum conditions were established including Imai model, Chai J C model, elasticity model and saturated soil seepage effective stress model.The settlement under vacuum tube well dewatering was forecasted based on analysis of the settlement data of vacuum dewatering field test using Regression, Gray Theory Model GM (1,1) and BP Neural Network.The vacuum seepage law and dewatering method of interlayer water were discussed with conclusions of3distribution forms of interlayer water including horizontal, sag and inclined distribution and the construction method when vacuum wells operate uphill under the condition of inclined distribution of aquiclude.更多还原