• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.09a
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• pp.184-187
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• 2001

This study presents procedure and analysis method for not well known slug interference tests. Results of the slug interference tests were compared with those of pumping and recovery tests and conventional slug tests.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.2
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• pp.89-96
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• 2000

Slug tests are the most widely used field method for quantification of hydraulic conductivity of porous media. Well recovery is affected by well casing, borehole radii, screened length, hydraulic conductivity, and specific storage of porous media. In this study, a new slug tests model was developed through finite element approximation and the validity and usefulness of the model were tested in various ways. Water level fluctuation in a well under slug test and cons-equent groundwater flow in the surrounding porous medium were appropriately coupled through estimation of well-flux using an iteration technique. Numerical accuracy of the model was verified using the Cooper et al. (1967) solution. The model has advantages in simulations for monitored slug tests, partial penetration, and inclusion of storage factor. Volume coverage of slug tests is significantly affected by storage factor. Magnitude and speed of propagation of head changes from a well increases as storage factor becomes low. It will be beneficial to use type curves of monitored head transients in the surrounding porous formation for estimation of specific storage. As the vertical component of groundwater flow is enhanced, the influence of storage factor on well recovery decreases. For a radial-vertical flow around a partially penetrated well, deviations between hydraulic estimates by various methods and data selection of recovery curve are negligible on practical purposes, whereas the deviations are somewhat significant for a radial flow.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.1
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• pp.14-22
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• 1999

Slug and pumping tests have been widely used to obtain hydraulic parameter estimates in the field. Although a variety of sources of error and uncertainty can be involved in the course of the test performance and data analysis, serious considerations on these sources are often neglected. In this study these various sources of error and uncertainty are analyzed or discussed using repeated slug and pumping test data and some guide lines are suggested to improve quality of parameter estimates from the slug and pumping tests.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.32-37
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• 1998

In this paper, the role of intermediate cover soils with respect to the leachate and gas flow is investigated from various field investigations and the hydraulic conductivity of the disposed waste is obtained using pumping and slug tests. From the results of field investigations, it was found that the flow of leachate and gas is prevented by the buried cover soils. The hydraulic conductivities of field pumping test and slug tests are well matched and stayed in the range of hydraulic conductivities of well compacted wastes in the literature.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.1-7
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• 2007

Slug/bail tests were conducted in sand layer (sbt-1 well), silty sand layer (sbt-2 well), and mixed sand and silty sand layer (sbt-3 well). Hydraulic conductivity and specific storage coefficient were estimated through slug/bail tests. Pore volumes of groundwater level drawdown zone for bail test were estimated by using hydraulic conductivity and specific storage coefficient. KGS model was most suitable interpretation method of slug/bail tests. Average hydraulic conductivity for slug/bail tests were estimated to be $6.65{\times}10^{-5}$ m/sec in sbt-1 well, $6.33{\times}10^{-6}$ m/sec in sbt-2 well, and $3.72{\times}10^{-5}$ m/sec in sbt-3 well. Average specific storage coefficient for slug/bail tests were estimated to be 0.0225 in sbt-1 well, 0.0177 in sbt-2 well, and 0.0259 in sbt-3 well. Dimensionless time and dimensionless wellbore storage were estimated by use of transmissivity, storativity, test time, and specification of test wells. And, dimensionless drawdown were selected by parameter ${\alpha}\;and\;{\beta}$ parameter from Cooper et al. (1967). Radius of influence were estimated by estimated dimensionless time, dimensionless wellbore storage, and dimensionless drawdown. The average radius of influnce for slug/bail tests were estimated to be 1.377 m in sbt-1 well, 1.253 m in sbt-2 well, and 1.558 m in sbt-3 well. Pore volume at groundwater level drawdown zone by dummy withdrawal for bail tests were estimated to be $145,636cm^3$ in sbt-1 well, $71,561cm^3$ in sbt-2 well, and $100,418cm^3$ in sbt-3 well. Pore volume excepted well volume at groundwater level drawdown zone by dummy withdrawal for bail tests were estimated to be $145,410cm^3$ in sbt-1 well, $71,353cm^3$ in sbt-2 well, and $100,192cm^3$ in sbt-3 well.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.99-109
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• 1999

In the case of domestic general waste landfills, cumulated leachate level is often formed in the landfill due to the waste of high moisture content and it becomes important to characterize the hydraulic properties of the disposed waste. Although many hydrologic studies have been peformed for leachate barriers and pheriperal subsurface environments, few studies have been done to investigate the hydraulic property of the disposed waste and cover soils and to analyse the leachate flow behavior within landfills. In this paper, the geotechnical properties of the waste and buried cover soils are identified through the field experiment including pumping and slug tests. The results of various tests show that the field density of the cover soils is somewhat higher than the maximum laboratory density of cover soils and the vertical flow of leachate and gas in the landfill is prevented by the buried cover soils. The hydraulic conductivities of field pumping test and slug tests are well matched and stayed in the range of hydraulic conductivities of well compacted wastes in the literature.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.338-347
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• 2006

연직차수벽은 오염지역이나 폐기물 매립장에서 오염된 지하수 (때로는 오염된 수증기) 흐름을 차단하거나 또는 오염지역의 정화처리시 효율을 높이기 위하여 외부로부터 지하수 흐름을 막기 위해 설치된다. 이 논문에서는 연직차수벽의 가장 중요한 설계요소인 차수벽체의 현장 투수성을 평가하는 방법들중 가장 보편적으로 사용되는 단공식 순간 변위시험 (slug test)을 소개한다. 연직차수벽에서 실행된 단공식 순간 변위시험 결과를 해석하기 위해서, 연직차수벽의 압축성과 기하학적인 특성을 고려한 수정된 linear curve fitting 방법을 제안하고 그 적용성을 case study를 통해 평가한다. 기존의 대수층 투수계수 산정에 이용된 curve fitting 방법들에 비하여 수정된 linear curve fitting 방법은 보다 정확한 연직차수벽체의 투수성을 평가하도록 한다.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.223-235
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• 2020

In this study, pulse tests were undertaken at an underground research facility, as part of in-situ hydraulic tests, to derive the hydrogeological characteristics of crystalline rock. The applicability of pulse tests for estimating the transmissivity of a fractured rock mass was evaluated by comparing the results to those from a slug test. Results from the pulse and slug tests were very similar for the test section, with both tests indicating low transmissivity. A slight difference between the results of pulse and slug tests, however, was observed in the section with the transmissivity larger than 1 × 10^-8 ㎡/s, which is likely due to the difference in the radii of influence of the tests. Furthermore, when the pulse test was conducted in permeable zones where transmissivity was larger than 1 × 10^-7 ㎡/s, it was difficult to produce accurate results. This lack of accuracy was due to the rapid recovery of the hydraulic head in these permeable test zones. When performing pulse tests, it was important to accurately measure the pressure when valves were opened and closed in order to apply the head change in the test section. Although it is difficult to derive the hydrogeological characteristics from pulse tests in areas with high permeability, these tests can be used as an economical test method for identifying hydrogeological characteristics in a relatively short time, especially when deriving the transmissivity of rocks with low permeability.

• The Journal of Engineering Geology
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• v.20 no.2
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• pp.203-212
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• 2010

The aim in this study is used to develop the remediation technologies for contaminated ground water. Slug, single well pumping and step-drawdown tests have been used to obtain hydraulic parameter estimates in the field. Slug tests yield hydraulic conductivity values using the Bouwer and Rice and C-B-P analysis methods. The mean and median hydraulic conductivity values of Bouwer and Rice method are $4.48{\times}10^{-3}$ and $1.16{\times}10^{-3}cm/sec$, respectively. On the other hand, C-B-P method gave mean and median hydraulic conductivity values of $2.37{\times}10^{-3}$ and $7.09{\times}10^{-4}cm/sec$, respectively. These analyses show a trend for the Bouwer and Rice method to yield lower hydraulic conductivity values in low permeability zones of granite in the study area. Sing well pumping test data were calculated through type curve in GW7, GW12 and MW9 wells. It could be interpreted that the differences of hydraulic conductivity and transmissivity values between GW7 and GW12, MW9 is related with fault clays and fractures in the bedrock among the wells. Step-drawdown tests were carried out in the KDPW1 and KDPW2 wells. The hydraulic parameter of KDPW1 and KDPW2 showed very litter difference between the values. The study of hydraulic parameter estimates can be used to purify in contaminated groundwater.

• Tunnel and Underground Space
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• v.19 no.4
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• pp.348-354
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• 2009

Slug test is a common characterization method that estimates aquifer hydraulic conductivity rapidly and economically. To characterize the hydraulic property near the borehole YS-4 in the Korea Atomic Energy Research Institute (KAERI) site, slug tests were performed, and oscillatory hydraulic responses were observed. We analyzed the observations with the modified Hvorslev and Bouwer&Rice methods considering the casing inertia, and then the results were compared with those from the general Hvorslev and Bouwer&Rice methods. The estimated hydraulic conductivities from the modified methods are ranged from $4.85{\times}10^{-6}$ to $5.44{\times}10^{-6}$ m/sec, but those from the general ones are ranged from $3.10{\times}10^{-6}$ to $3.63{\times}10^{-5}$ m/s, which shows that the oscillatory responses should be analyzed with consideration of the flowing water inertia effect.