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Comparison of methods to calculate coefficient of permeability of sandy cobble aquifer based on pumping tests
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摘要: 含水层的渗透系数是基坑降水设计中的重要参数，不同计算方法得出的渗透系数也不同，应取最适合的计算方法，以免产生较大误差。基于砂卵石潜水含水层现场单井抽水试验结果，分别利用Dupuit-Kusargent法、Thiem法、直线斜率法及水位恢复法等四种方法来计算潜水含水层渗透系数，对比各方法计算的渗透系数所模拟的水位值与现场实测值的偏差，讨论了造成这种偏差的原因，指出了各种方法的优缺点和适用性。研究结果表明，Dupuit-Kusargent法误差最大，直线斜率法次之，水位恢复法和Thiem法误差较小。同时Dupuit-Kusargent法计算结果受流量影响较大，一致性较差，其他方法结果的一致性较好。在计算砂卵石含水层的渗透系数时，如有2个以上观测井，应优先选用Thiem法；无观测井的情况下选用水位恢复法；有1个观测井且其降深-时间对数关系直线段明显时可选用直线斜率法。Abstract: The coefficient of permeability of aquifer is an important hydrogeological parameter in foundation pit dewatering design. The calculated coefficient of permeability of the same soil layer by different calculation methods may be different, thus it is very important to select the most suitable calculation method for a certain soil layer to avoid large errors. Based on the test results of single well pumping tests in sandy cobble ground, four common methods, i.e. Dupuit-Kusargent method, Thiem method, straight-line slope method and water level recovery method are used to calculate the coefficient of permeability of aquifer. The difference between the simulated water level and the field measured value is compared, the reasons resulting in the differences are discussed, and the advantages, disadvantages and applicability of each method are pointed out. The analysis results show that the error of Dupuit-Kusargent method is the largest, that of the straight-line slope method is the second, and the errors of water level recovery method and Thiem method are small. Furthermore, the results from Dupuit-Kusargent method are greatly affected by the pumping flow rate, and its consistency is poor. The consistency of the results from other methods is good. For determination of the coefficient of permeability for sandy cobble aquifer, Thiem method should be preferred when there are more than two observation wells. The straight-line slope method can be used when there is an observation well, and the falling depth and the logarithm of time are in good agreement with the linear relationship. The water level recovery method can be used when there is no observation well. It is not recommended to use Dupuit-Kusargent method due to its large error.
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Key words:
- sandy cobble /
- aquifer /
- permeability coefficient /
- pumping test
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图 1 试验基坑周围降水井布置（单位：m）
Figure 1. Layout of dewatering well around test foundation pit (unit: m)
图 2 第1组抽水试验降水井和观测井的降深时程曲线
Figure 2. Time history curves of dewatering and observation wells in the first group of pumping tests
图 3 第2组抽水试验降水井和观测井的降深时程曲线
Figure 3. Time history curves of dewatering and observation wells in the second group of pumping tests
图 4 第1组抽水试验观测井s-lgt关系
Figure 4. Straight-line fitting for s-lgt relation of observation well in the first group of pumping tests
图 5 水位恢复试验抽水井的s*-lgt关系拟合直线
Figure 5. Fitting for s*-lgt relation of pumping well in water level recovery tests
表 1 抽水试验水位稳定后各井的最终水位
Table 1. Final water level in each well after water level is stable in pumping tests
单位：m 试验编号 抽水井 观测井J27 观测井J38 试验编号 抽水井 观测井J27 观测井J38 J28-369 10.20 11.20 11.32 J39-348 10.38 11.43 11.32 J28-520 8.74 10.80 10.99 J39-442 9.62 11.12 10.97 J28-640 7.18 10.40 10.65 J39-575 7.68 10.80 10.68 
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表 2 不同方法计算的渗透系数
Table 2. Coefficients of permeability calculated by different methods
单位：m/d 试验
编号Dupuit-
Kusargent法Thiem
公式法直线斜率法 水位
恢复法J27 J38 J28-369 4.7 16.6 24.1 24.9 15.9 J28-520 7.5 14.3 22.6 22.0 13.2 J28-640 11.2 13.8 21.2 20.7 − J39-348 3.8 17.4 24.6 24.1 16.1 J39-442 5.6 15.1 24.0 22.5 13.5 J39-575 9.5 14.4 22.4 22.5 − 平均值 7.1 15.5 23.0 15.3
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表 3 观测井水位模拟值及其偏差
Table 3. Simulated water level and deviation of observation well
单位：m 渗透系数
获取方法模拟J27
水位J27水位
偏差模拟J28
水位J28水位
偏差Dupuit法 10.54 0.58 10.20 0.77 水位恢复法 11.03 0.09 10.85 0.12 直线斜率法 11.33 0.21 11.19 0.22 Thiem法 11.08 0.04 10.09 0.07
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表 4 不同计算方法的优缺点对比
Table 4. Comparison of advantages and disadvantages of different calculation methods
特 点 稳定流计算方法 非稳定流计算方法 Dupuit-Kusargent法 Thiem公式法 直线斜率法 水位恢复法 优点 试验过程和计算简单 试验过程简单，简单土层的
计算有较高准确性记录了抽水过程中水位的
变化，方法严谨准确反映了水位的变化，
结果精确且一致性较好缺点 结果一致性较差，不适用复
杂水文地质条件下的计算需设观测井且复杂水文地质
条件下的计算不适用对试验观测数据的准确性
要求高当水流为三维渗流时，
结果会产生较大误差适用性 试验场地无观测井且水文
地质条件简单的土层试验场设有观测井且水文
地质条件简单的土层观测井降深-时间对数关系
直线段明显的土层试验场地无观测井且水文
地质条件较复杂的土层
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[1] THEIS C V. The relation between the lowering of the Piezometric surface and the rate and duration of discharge of a well using ground-water storage[J]. Eos, Transactions American Geophysical Union, 1935, 16(2): 519-524. doi: 10.1029/TR016i002p00519 [2] 尚银生, 阎金钟, 李康. 对《基坑降水计算中应用裘布依公式的问题》一文的理解与体会[J]. 工程勘察,2012,40(9):35-37. (SHANG Yinsheng, YAN Jinzhong, LI Kang. Understanding and experience on the paper “The problem of Dupuit formula application in foundation pit dewatering calculating”[J]. Geotechnical Investigation & Surveying, 2012, 40(9): 35-37. (in Chinese) [3] 吕斌泉, 冯晓腊, 熊宗海. 武汉古河道承压水井流理论及在基坑降水中应用[J]. 岩土工程学报,2020,42(3):533-541. (LÜ Binquan, FENG Xiaola, XIONG Zonghai. Theory of artesian well flow in ancient river in Wuhan and its application in foundation pit dewatering[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(3): 533-541. (in Chinese) [4] 顾宝和. 基坑降水计算中应用裘布衣公式的问题[J]. 工程勘察,2011,39(10):84-87. (GU Baohe. Issues on applications of Dupuit’s equation in the calculation for dewatering of foundation pit[J]. Geotechnical Investigation & Surveying, 2011, 39(10): 84-87. (in Chinese) [5] 竺新强, 马强. 长江漫滩抽水试验与水文地质参数计算[J]. 地质学刊,2019,43(2):315-321. (ZHU Xinqiang, MA Qiang. Pumping test and hydrogeological parameter calculation of floodplain in the Yangtze River[J]. Journal of Geology, 2019, 43(2): 315-321. (in Chinese) doi: 10.3969/j.issn.1674-3636.2019.02.018 [6] 林志斌, 李元海, 桂常林, 等. 定流量下潜水非完整井稳定流计算方法[J]. 岩土工程学报,2013,35(12):2290-2297. (LIN Zhibin, LI Yuanhai, GUI Changlin, et al. Method for steady flow of partially penetrating well in phreatic aquifer under constant flow[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(12): 2290-2297. (in Chinese) [7] 秦甜甜, 丁国辉. 基于抽水试验的水文地质参数计算方法研究[J]. 水资源开发与管理,2018(1):69-73. (QIN Tiantian, DING Guohui. Study on hydrogeological parameter calculation method based on water pumping test[J]. Water Resources Development and Management, 2018(1): 69-73. (in Chinese) [8] 中华人民共和国建设部. 供水水文地质勘察规范: GB 50027—2001[S]. 北京: 中国计划出版社, 2004. Ministry of Construction of the PRC. Standard for hydrogeological investigation of water-supply: GB 50027—2001[S]. Beijing: China Planning Press, 2004. （in Chinese） [9] 王明章. 裘布依地下水井流计算公式有关问题讨论[J]. 贵州地质,2011,28(2):118-121. (WANG Mingzhang. Discussion about dupuit’s equation of groundwater well flow[J]. Guizhou Geology, 2011, 28(2): 118-121. (in Chinese) doi: 10.3969/j.issn.1000-5943.2011.02.008 [10] 陈孙雨. 单井水力学[M]. 北京: 中国建筑工业出版社, 1977: 185-188. CHEN Sunyu. Single well hydraulics[M]. Beijing: China Construction Industry Press, 1977: 185-188. （in Chinese） [11] 陈崇希, 林敏. 地下水动力学[M]. 武汉: 中国地质大学出版社, 1999: 59-60. CHEN Chongxi, LIN Min. Groundwater dynamics[M]. Beijing: China University of Geosciences Press, 1999: 59-60. （in Chinese） [12] 朱宏军, 黄选明, 胡莉莉, 等. 煤矿水文地质勘探中稳定流抽水试验确定水文地质参数讨论[J]. 中国安全生产科学技术,2014,10(3):24-29. (ZHU Hongjun, HUANG Xuanming, HU Lili, et al. Discussion on determining the hydrogeological parameters in steady flow pumping test of coal mine hydrogeological exploration[J]. Journal of Safety Science and Technology, 2014, 10(3): 24-29. (in Chinese) [13] 朱保坤, 苟联盟, 柴永进, 等. 基于抽水试验的渗透系数计算方法对比与研究[J]. 科技创新与应用,2017(27):71-72. (ZHU Baokun, GOU Lianmeng, CHAI Yongjin, et al. Comparison and Research on calculation method of permeability coefficient based on pumping test[J]. Technology Innovation and Application, 2017(27): 71-72. (in Chinese) [14] 刘兆昌, 李广贺, 朱琨. 供水水文地质[M]. 北京: 中国建筑工业出版社, 2011: 100-101. LIU Zhaochang, LI Guanghe, ZHU Kun. Hydrogeology of water supply[M]. Beijing: China Architecture & Building Press, 2011: 100-101. （in Chinese） -
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