地铁隧道洞内水平真空超前降水数值模拟  

Numerical simulation of horizontal vacuum advance dewatering in subway tunnel

作　　者：陈恺[1,2] 赵国庆 唐汐 杨扬[1,2] CHEN Kai;ZHAO Guoqing;TANG Xi;YANG Yang(Beijing MTR Construction Administration Co.,Ltd.,Beijing 100068,China;Beijing Key Laboratory of Fully Automatic Operation and Safety Monitoring for Urban Rail Transit,Beijing 100068,China;School of Civil Engineering,Shenyang Jianzhu University,Shenyang 110168,China)

机构地区：[1]北京市轨道交通建设管理有限公司,北京100068 [2]城市轨道交通全自动运行系统与安全监控北京市重点实验室,北京100068 [3]沈阳建筑大学土木工程学院,沈阳110168

出　　处：《建筑结构》2025年第1期145-150,共6页Building Structure

基　　金：国家自然科学基金项目(52208356);北京市轨道交通建设管理有限公司双创基金项目(SCJJ2021002)。

摘　　要：针对低渗透性粉细砂、砂质粉土交界面层间水抽排困难的问题,以北京地铁3号线某区间降水工程为背景,建立了水平真空降水三维数值模型。在与现场试验结果对比验证数值模型有效性的基础上,研究了抽水时间、抽水压力、水平井长和井间距等参数对水平真空降水效果的影响规律。结果表明:单井出水速度在抽水初期会快速衰减,抽水1d后出水速度降低约32%,此后抽水速度基本趋于稳定;水平真空抽水的出水量随抽水压力的增加而显著增大;水平井越长,其负压影响区范围越大,当单井长从5m增至25m,以0.04MPa为界的负压影响区宽度从4m增至13.5m,增幅237.5%;当双井间距从3m增至18m,双井间真空度0.055MPa的负压区从沿全长重叠逐渐发展至不再重叠,在设计井间距时宜考虑能够形成一定的负压重叠区以保证降水效果。研究成果可为该类降水设计和工程应用提供参考。Aiming at the problem of difficult water pumping and draining in the interlayer interface of low-permeability fine powdered sand and sandy powdered soil,a three-dimensional numerical model of horizontal vacuum dewatering was established with the background of precipitation engineering for an interval of Beijing Metro Line 3.Based on comparing with the field test results and verifying the validity of the numerical model,the efficiency of the horizontal vacuum dewatering was evaluated by analyzing various parameters such as pumping duration,pumping pressure,horizontal well length and spacing.The results show that initial findings reveal a swift decrease in water discharge rate from a single well at the start of pumping,which drops by approximately 32% one day before stabilizing,and then the pumping speed will basically stabilize.The water yield from horizontal vacuum pumping notably increases with higher pumping pressure.The longer the horizontal well is,the larger the range of the negative pressure affected zone is.When the single well length increases from 5m to 25m,the width of the negative pressure affected zone bounded by 0.04MPa increases from 4m to 13.5m,an increase of 237.5%.When the distance between the two wells increases from 3m to 18m,the negative pressure zone with a vacuum of 0.055MPa between the two wells gradually develops from overlapping along the full length to no longer overlapping.When designing the well spacing,it should be considered to form a certain negative pressure overlap zone to ensure the precipitation effect.The research results can provide reference for the design and engineering application of this kind of precipitation.

关 键 词：低渗透性粉细砂地层 层间水 水平真空井 孔隙水压力 数值模拟 

分 类 号：TU463[建筑科学—结构工程]