承压-无压转换下阶梯降深抽水试验解译研究  

Explanation Study on Step-draw Down Pumping Test Under Conversion of Confinedto Unconfined

作　　者：张璐 赵华 郝世鹏 刘红兵 王一兆 张荣辉 Zhang Lu;Zhao Hua;Hao Shipeng;Liu Hongbing;Wang Yizhao;Zhang Ronghui(Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广东广州510010

出　　处：《市政技术》2025年第2期73-79,共7页Journal of Municipal Technology

摘　　要：阶梯降深抽水试验是水文地质勘察的重要手段,其在实施过程中容易经历承压向无压的转变,且井损也呈现一定变化。针对现有模型无法准确解译该类型抽水试验的问题,提出了一项新的承压转无压的阶梯降深抽水试验模型及其解析解,同时开展了相应的场地试验,并借助粒子群优化算法实现了场地含水层渗透系数、储水系数、井损系数和承压-无压转换临界时间等多个参数的同步反演。研究结果表明,新提出的解析解比已有研究提出的解析解更好地拟合了井中的降深数据,忽略承压-无压的转换将导致井内降深的低估,该场地试验承压到无压的转换导致井损系数值下降了89%,表明不带观测孔的阶梯降深抽水试验解译时有必要调整井损系数来适应承压向无压的转换。该阶梯降深抽水试验新解析解及其场地应用丰富了当前的井流动力学理论以及含水层参数反演技术。Step-draw down pumping test is an important method in hydrogeological investigation.It often inevitably undergoes a conversion of confined to unconfined during the implementation,while the well loss also shows certain changes.In response to the problem that existing models cannot accurately interpret this type of pumping test,a new analytical solution was proposed for step-drawdown pumping tests undergoing confined to unconfined conversion in this study;Meanwhile,a field test was conducted.The multiple parameters including hydraulic conductivity,stor-age coefficient,well loss coefficient,and the critical time for confined to unconfined conversion were simultaneously inverted by particle swarm optimization algorithm.The results indicated that the newly proposed analytical solutions better fitted the observed drawdown data than previous solutions.That ignoring the conversion in the model causes an underestimation of the drawdown in the well.For the field test,the confined to unconfined conversion resulte in an 89%decrease in the well loss coefficient,indicating the necessity of adjusting the well loss coefficient to adapt to the confined to unconfined conversion in the interpretation.This new analytical solution for pumping tests and its field application have enriched the current theories of well hydraulics and aquifer parameter inversion techniques.

关 键 词：阶梯降深抽水试验 承压-无压转换 井损 解析解 粒子群优化算法 

分 类 号：P641[天文地球—地质矿产勘探]