温度对潜水含水层底部疏放水井渗流的影响  

Influence of temperature on groundwater seepage in dewatering wells at the base of phreatic aquifers

作　　者：王文学[1,2] 吴冰 郝清扬 Wang Wenxue;Wu Bing;Hao Qingyang(North China University of Water Resources and Electric Power,Zhengzhou 450045,Henan,China;Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering,Zhengzhou 450045,Henan,China;Henan Department of Finance,Zhengzhou 450008,Henan,China)

机构地区：[1]华北水利水电大学,河南郑州450045 [2]河南省岩土力学与结构工程重点实验室,河南郑州450045 [3]河南省财政厅,河南郑州450008

出　　处：《地质学刊》2024年第4期435-440,共6页Journal of Geology

基　　金：国家自然科学基金资助项目“应力恢复对采动裂隙岩体结构及阻隔水能力演化的影响机制”(41602298);河南省高等学校重点科研项目“考虑水压传递速率及分布特征的坑道水害精准防控技术研究”(25A170005);河南省青年骨干教师培养项目“含水层仰斜疏放水孔负压抽吸增渗及水压传递速率演化机制”(2023GGJS076)。

摘　　要：含水层中水的渗流速度与渗透系数关系密切,温度变化会引起含水层渗透系数改变,导致抽灌系统或者疏放水孔(井)的涌水量产生较大差异。为探究温度对潜水含水层底部疏放水井流量的影响,设计夹角60°的扇形体渗流砂槽系统,分别开展水温9、21℃下不同井长的非完整井疏放水渗流砂槽试验。结果表明:完整疏放水井可以采用Dupuit公式计算流量,其结果与疏放水试验结果基本一致;饱和自由水带及饱和毛细水带可有效隔绝空气进入井片,非完整井的疏放水效果与完整井类似;温度升高会引起水的动力黏滞系数下降,多孔介质中水的渗透速度加快,疏放水井流量增大;利用传统Dupuit公式计算非完整疏放水井流量的误差较大,将降深与井长之和(S_(w)+l_(w))代替S w作为降深代入Dupuit进行修正,精确度较高。The seepage velocity of water in aquifers is closely related to the permeability coefficient,which is significantly influenced by temperature variations.These changes in permeability can lead to considerable differences in water discharge from dewatering wells or pumping systems.To investigate the effect of temperature on the flow rates of dewatering wells at the base of phreatic aquifers,a 60°wedge-shaped seepage sand tank system was designed.Experiments were conducted under water temperatures of 9℃and 21℃for dewatering wells of varying lengths in an incomplete well configuration.The results showed that the flow rate of complete dewatering wells could be calculated using the Dupuit formula,with calculated values closely matching experimental results.The free water-saturated zone and capillary-saturated zone effectively prevent air intrusion into the well sections,resulting in incomplete wells performing similarly to complete wells in drainage.Elevated temperatures reduce the dynamic viscosity of water,accelerating seepage in porous media and increasing dewatering well discharge.However,using the traditional Dupuit formula to calculate flow rates in incomplete dewatering wells yields significant errors.Replacing the drawdown depth(S_(w))with the sum of the drawdown and well length(S_(w)+l_(w))in the Dupuit formula significantly improves accuracy.

关 键 词：砂槽试验 温度 疏放水井 流量 Dupuit公式 

分 类 号：P641.132[天文地球—地质矿产勘探]