非承压含水层底部单孔疏放水渗流特征  

The seepage characteristics of a single well dewatering from an unconfined aquifer bottom

作　　者：李洋 王文学[2] 肖航 孙毅 王运 狄梦娜 LI Yang;WANG Wenxue;XIAO Hang;SUN Yi;WANG Yun;DI Mengna(Henan Province Bureau of Hydrology and Water Resources,Zhengzhou 450003,China;Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;Henan Province Geology and Mining Construction Engineering LTD,Zhengzhou 450007,China)

机构地区：[1]河南省水文水资源局,河南郑州450003 [2]华北水利水电大学,河南省岩土力学与结构工程重点实验室,河南郑州450045 [3]河南省地矿建设工程(集团)有限公司,河南郑州450007

出　　处：《煤田地质与勘探》2019年第3期154-159,165,共7页Coal Geology & Exploration

基　　金：国家自然科学基金项目(41602298);河南省高等学校重点科研项目(16A410004)~~

摘　　要：由含水层底部向上施工疏放水孔(井)进行疏水降压是保证煤矿安全开采的重要措施之一,该类疏放水孔与地面抽水井的渗流特征具有显著差别。为了研究井下疏放水孔的渗流特征,以非承压含水层底部单井疏放水孔为例,采用数值模拟的方法对其渗流特征进行研究。研究结果表明,当疏放水井的井长lw小于临界长度lc时,即lw<lc,疏放水井上部含水层孔隙水压力大于0,且由下而上呈先增加后减小的分布规律,渗流量与井长呈指数函数关系增加;当lw≥lc时,疏放水非完整井的渗流特征及渗流量与完整井相同;渗流量随井半径增加呈指数关系增加,且指数小于1;将s+lw代替水位降深s对裘布依(Dupuit)潜水完整井计算公式进行修正,当lw<lc时,采用修正的Dupuit潜水完整井计算公式计算疏放水非完整井渗流量更精确。该研究结果对认识井下疏放水井上部孔隙水压力分布特征及合理布置疏放水井具有重要的借鉴意义。Dewatering from an aquifer bottom for drain and depressurization is one common method to ensure safety mining.This method is significantly different from pumping from the ground.In order to study the seepage characteristics of the dewatering hole(well),the seepage characteristics of a single well dewatering from an uncon-fined aquifer bottom was taken as an example and studied using numerical simulation method.The results show that when lw<lc,the pore water pressure above the dewatering well is greater than zero,which presents the rule of increasing first then decreasing from bottom to top,and the seepage flow increases with well length following an exponential function relationship.When lw≥lc,the seepage characteristics and seepage flow of the incomplete de-watering well is the same with the complete dewatering well.The seepage flow increases with the well radius fol-lowing a power relationship with the exponent less than 1.By substituting s+lw into Dupuit formula for unconfined complete wells instead of drawdown s,a revised formula was proposed which could be used to calculate water flow for uncomplete dewatering wells with a more accurate result.This study will provide an important theoretical basis for understanding the seepage characteristics and more effectively drilling of the dewatering wells.

关 键 词：含水层 疏放水井 涌水量 Dupuit公式 

分 类 号：P641.4[天文地球—地质矿产勘探]