• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.4
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• pp.4209-4217
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• 1976

The purpose of this thesis is to search for the determination method of pumping rates in the existing tube wells for irrigation. Pumping tests were carried out for the twelve test tube wells which were selected in the provinces of Kyounggi, Kangwon, Chungbuk and Chungnam. The depths, static water levels, pumping levels, drawdowns and yields of tube wells were measured in the pumping tests, and a centrifugal pump with 3 inches diameter, a 5 HP motor and a 90$^{\circ}$ V-notch were used in the pumping tests. The average coefficient of transmissibility calculated by Chow's and Jacob's methods is 0.0336 square meter per second, and the average pumping rate calculated by Thiem's, Smreker's, Brinkhaus' and Theis' formulae, is 919 cubic meter per day, Therefore, the ground water storage in the test areas is comparatively abundant. Correlation between pumping rates and depths of tube wells is not in existence. Also, correlation between pumping rates and the thickness of aquifer is not found in this experiment. This shows that the depths of some tube wells are deep and their thicknesses of aquifer are thick, but their ground water storages are poor, and that the depths of some tube wells are shallow and their thicknesses of aquifer are thin, but their ground water storages are abundant. It seems that the test tube wells are influenced by the peculiar characteristics that the ground water in the test areas is free ground water in alluvium layer closely related with surface water. As drawdown increases, pumping rate decreases, and as the coefficient of transmissibility increases, pumping rate also increases. Namely, there are negative correlation between pumping rate and drawdown, and positive correlation between pumping rate and the coefficient of transmissibility. Judging from the results of the pumping tests in these tests areas, the pumping rate calculated by the formula, {{{{ { Q}_{m } =Q { ( { { S}_{ m} } over { TRIANGLE S } )}^{ { 2} over {3 } } }}}} used traditionally, is likely to be higher than real pumping rates. The formula, {{{{ { Q}_{m } =Q { { H}^{ 2} } over { (2H- TRIANGLE S) TRIANGLE S} }}}} derived from Thiem's theory, is looked upon as the reasonable one to detemine pumping rates in the existing tube wells for irrigation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.413-420
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• 2020

In this study, a new lab-scale test equipment was developed to evaluate the variation of concrete workability after pumping. The equipment was designed to simulate the pressure and shearing applied to concrete during actual pumping. In order to examine the feasibility of evaluating variation of concrete workability through lab-scale test equipment, real-scale pumping tests and lab-scale tests were performed together. The design strength of concrete used in the both tests was 24, 35, and 60MPa, and the length of pipe used in pumping tests was 130, 304, and 518m. The lab-scale tests were performed in consideration of actual pumping conditions(pressure, shearing, and pumping duration time). The workability(slump or slum flow) of concrete was measured before test, after the pumping test, and after lab-scale test. In all tests, workability of all concrete mixtures decreased. In addition, the results of both tests were measured greatly similarly.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.2
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• pp.3410-3419
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• 1974

The purpose of this study is to find out the correlation between pumping rates and influential factors in the tube wells for irrigation through the analysis of various statistical data of the existing tube wells for irrigation and pumping tests. Statistical data of the existing tube wells for irrigation were collected from the authorities concerned, and pumping tests were carried out for twelve tube wells. The results of this study are summarized as follows: 1. The drilled tube wells are the most useful among various tube wells in securing pumping rates. 2. The enlargement of well diameter or the improvement of pumping equipments is necessary in drilled tube wells with pumping rates more than 806 ㎥/day, and the adjustment of foot valves or the special control of pumping equipments is necessary in tube wells with pumping rates less than 300 ㎥/day. 3. The choking of aquifer and slits can be prevented by removing earth and sand piled in tube wells. 4. The increase of well loss and the destruction of aquifer can be prevented by determining the optimum pumping rates through the step draw down tests. 5. The thickness of gravel packing is rather thin in drilled tube tube wells. 6. High pamping rates can be gained by deepening the depth of tube wells in the place the ground water storage is abundant, the thickness of aquifer is thick. and the depth of tube wells is deep. 7. Higher pumping rates can be obtained by constructing tube wells in the place where the drawdown is little and the coefficient of transmissibility is large.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.987-993
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• 2004

The status of mud-pumping in the existing railroad lines were investigated and real-scale tests simulating mud-pumping phenomena were carried out to analyze its mechanism. The penetration of ballast material into the subgrade and the cause of mud-pumping are explored. The results of the investigation and tests will be used to develop the new method and materials for the prevention of mud-pumping.

• 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.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.446-450
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• 2005

Hydraulic conductivity of unconsolidated media can be determined by aquifer tests, laboratory tests and empirical equations based on grain size analysis. Commonly, the different methods give different hydraulic conductivities. Grain size measurements were done to determine hydraulic conductivity, using 184 soil samples collected from eight boreholes in a riverbank filtration area, Daesan-Myeon, Changwon City, Korea, Pumping tests were conducted at the riverbank filtration area. The average hydraulic conductivity by the empirical relations from grain size measurements comes out around $10^{-2}m/s$, 22 to 55 times higher than by the pumping test analyses. The hydraulic conductivity obtained from the empirical equations is interpreted to have a relationship with steady-state condition while that obtained from the pumping tests is interpreted to have a relationship with unsteady-state condition. Thus, hydraulic conductivity obtained from various methods should be critically analyzed for reasonable management of groundwater development.

• 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.

• Journal of the Korean earth science society
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• v.29 no.5
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• pp.396-407
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• 2008

Hydrogeologic properties of a well field around middle mountainous areas in Pyosun, Jeju volcanic island were examined based on water level monitoring, geologic logging and pumping test data. Due to the alternating basaltic layers with varying permeability in the subsurface, it is difficult to analyze the hydraulic responses to artificial pumping and/or natural precipitation. The least permeable layer, detrital materials with clay, is found at a depth of 200 m below surface, but it is not an upper confining bed for lower main aquifer. Nevertheless, this layer may serve as a natural barrier to vertical percolation and to contaminant migration. Water levels of the production wells are dominantly affected by pumping frequently, while those of the remote observation wells are controlled by ambient precipitation. Results of pumping tests revealed a possible existence of horizontal anisotropy of transmissivity. However, some results of this study include inherent limitations enforced by field conditions such as the consistent of groundwater production and the set of time periods for the cessation of the pumping prior to pumping tests.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.70-76
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• 2012

Recently, because people are taking a great interest in the water supply system and the related facilities are getting larger, the surge suppression is very important problem. The waterhammer occurs when the pumps are started or stoped for operation or tripped due to the power failure. As the waterhammer problems as a result of the pump power failure were very serious, these situations were carefully investigated. Accordingly, we carried out both numerical simulations and field tests to confirm the safety of Juam intake pumping station in which had the in-line pumps. In this paper, it was reviewed that the water supply system has the reliability on the pressure surge, in case the air chambers were installed at both the inlet and the oulet of the in-line pumping station. From the numerical simulations, we found that negative pressure occurred at the inlet disappeared and high pressure occurred at the outlet reduced due to the air chambers. And these results of numerical simulations verified by the field tests. The field tests carried out in case of normal start, normal stop, one and two of pumps emergency stop. By results of simulations and field tests, we are sure that Juam intake pumping station in which have the air chambers is safe for the waterhammer. In addition, we suggested the operation methods of facilities for safe maintenance of the pumping station.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.451-459
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• 2012

At the Korea Land and Housing Corporation(LH), concretes with high design strength of 50 MPa and 80 MPa that are composed only of ordinary Portland cement, blast furnace slag, and fly ash are developed. To determine whether the developed high strength concretes have the same properties when they are produced in batch plant(B/P) condition in the ready mixed concrete plant, and as existing high strength concretes, field tests are performed and material properties are evaluated. To investigate the material properties of the high strength concretes before and after pumping, compressive strength, flowability, air content, hydration temperature, pumping and compactability are evaluated. In field tests, before and after pumping, flowability satisfied the relevant criteria. In terms of air content, while it was slightly decreased after pumping, it satisfied the requirements. Hydration temperature criteria were satisfied, and compactability was excellent as well. The study found that the developed ternary high strength concretes have the same properties as existing high strength concretes. They can also be useful for the construction of high-rise buildings, as they are economical.