范丹丹,陈群,亓立成,等. 由抽水试验计算砂卵石含水层渗透系数的方法对比[J]. 水利水运工程学报,2021(4):54-60. doi: 10.12170/20200829001
引用本文: 范丹丹,陈群,亓立成,等. 由抽水试验计算砂卵石含水层渗透系数的方法对比[J]. 水利水运工程学报,2021(4):54-60. doi: 10.12170/20200829001
(FAN Dandan, CHEN Qun, QI Licheng, et al. Comparison of methods to calculate coefficient of permeability of sandy cobble aquifer based on pumping tests[J]. Hydro-Science and Engineering, 2021(4): 54-60. (in Chinese)). doi: 10.12170/20200829001
Citation: (FAN Dandan, CHEN Qun, QI Licheng, et al. Comparison of methods to calculate coefficient of permeability of sandy cobble aquifer based on pumping tests[J]. Hydro-Science and Engineering, 2021(4): 54-60. (in Chinese)). doi: 10.12170/20200829001

由抽水试验计算砂卵石含水层渗透系数的方法对比

Comparison of methods to calculate coefficient of permeability of sandy cobble aquifer based on pumping tests

  • 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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