• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.396-403
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• 2016

This study is based on the evaluation of a single component injection type adhesive repair material and a new 2 component type used in leakage of underground concrete structures. The studies showed that based on different mix ratio of the 2 component type adhesive sealant comprised of an asphalt main and latex mixture agent the viscosity of the material compound differed significantly. Based on a permeability testing, injection and economic efficiency, and performance, the appropriate ratio was determined to be 6:1 and was proceeded to the KS F 4935 evaluation method. The 2 component type adhesive sealant uses a static mixer and a cartridge type container for the injection procedure and was able to satisfy the evaluation criteria outlined in the KS F 4935 standard.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.11-20
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• 2020

This study introduced the compact grouting method that can be used for improving soft ground and restoring buildings with unequal subsidence. The pump used in the traditional compact grouting method is a system that injects one hole each, which reduces the construction efficiency, and the analog injection method manually manages the construction by field workers, making it difficult to manage consistent quality. Pump and quality control system were developed to solve problems in existing construction. Since field supervisor determines amount of injected materials by using analog equipment and controls manually, it is difficult to manage consistent quality of construction. Therefore, the quality control system was developed in order to solve that problem. The quality control system consists of automatic mixing system of injection materials, multiple simultaneous injection pumps, and injection management monitoring system. Performance of the quality control system was verified through on-site testing, and ground improvement performance was verified through quality testing after testing and testing of the compact grouting method. Therefore, it is expected that the integrated quality control system developed will improve the quality assurance and efficiency and stability of construction at sites where construction and quality verification are difficult.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.288-291
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• 2005

방사성폐기물 처분연구의 일환으로 단열 암반지역의 지하수 유동에 있어서 각 단열조의 투수량계수를 알아보기 위하여 연구지역에 설치된 3기의 시추공에서 초음파 검층, 정압주입시험 및 유동차원 해석을 수행하였다. 단열은 방향성, 틈의 크기 등의 그 분포 특성으로 인해 각 시험구간내의 지하수 유동에 있어서, 유동형태 및 단열투수량계수를 좌우하므로 일반적으로 수리특성에 널리 이용되는 다공성매질의 연속체 개념을 통한 해석의 적용에 신중성을 고려할 필요가 있다.

• 전기의세계
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• v.13 no.3
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• pp.103-107
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• 1964

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.269-278
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• 2020

In this study, the effects of groundwater artificial recharge through vertical wells in the upper small basin are preliminarily evaluated by using field injection test and a 3-D numerical model. The injection rate per well in a model is set to 20, 37.5, 60, and 75 ㎥/day based on the results of field injection test, groundwater levels, and hydraulic conductivities estimated from particle size analysis, and a numerical model using MODFLOW is conducted for 28 cases, which have diverse injection intervals, in order to estimated the changes of groundwater level and water balance after injection. Groundwater level after injection does not show a linear relationship with the injection rate per well, and the cumulative effect of artificial recharge decreases and the timing of maximum water level rise is shortened as the injection interval becomes longer. In four cases of continuous injection with total injection rate of 1,200 ㎥, it is revealed that the recharge effect is analyzed as 36.5~65.3% of the original injection rate. However, it will be more effective if the artificial recharge system combined with underground barrier is introduced for the longer pumping during a long and severe drought. Additionally, it will be possible to build a stable artificial recharge system by an establishment of efficient scenario from recharge to pumping as well as an optimization of recharge facilities.

• Journal of Energy Engineering
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• v.26 no.3
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• pp.71-77
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• 2017

In the event of loss of coolant accident (LOCA) and station black out (SBO) in the primary system of a nuclear reactor, the coolant water should be injected to reactor coolant system (RCS) without any intervention of operators or active components. To satisfy the requirements, hybrid safety injection tank (Hybrid SIT) was suggested by Korea Atomic Energy Research Institute (KAERI). The pressure equalizing time of Hybrid SIT is an important parameter to determine the timing of coolant injection. To predict the pressure equalizing time of the Hybrid SIT, a separate effect test facility was constructed and sensitivity tests were conducted in various conditions. The main parameter determining the pressure equalizing time was obtained from separate effect test (SET) results. The wall of condensation on the inner wall of SIT and direct contact condensation on the water surface affected to the pressure equalizing time very much. In this study, the effect of each condensation phenomena on pressure equalizing time was quantitatively analyzed from results of SET and a prediction method of pressure equalizing time was proposed.

• Geotechnical Engineering
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• v.11 no.3
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• pp.123-138
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• 1995

To study the grout flow in jointed rock, various nurser characteristics of grout in a single joint plane and two-dperorbed. The joint plane is described as a channel nets properties of grout are considered. To deal with various prob generator and i oint network generator are used. A loss of head due to friction in laminal flow is adopted to between the grout and joint wall. The grout flow is stopped, setting time. To consider this phenomenon, the idea of maxim From the results of numerical simulation on the single jai etration of grout is confirmed. The basic principles for the ation and the selection of the grout are presented. Correlation ant and grouting pressure is defined by analyzing the effects grout flow. Finally, the grout flow around a tunnel is simulate ins grouting operation for jointed rock mass.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.348-372
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• 2023

In relation to the high-level radioactive waste disposal project in deep fractured rock aquifer environments, it is essential to evaluate hydrogeological characteristics for evaluating the suitability of the site and operational stability. Such subsurface hydrogeological data is obtained through in-situ tests using boreholes excavated at the target site. The accuracy and reliability of the investigation results are directly related to the selection of appropriate test methods, the performance of the investigation system, standardization of the investigation procedure. In this report, we introduce the detailed procedures for the representative test method, the constant pressure injection test (CPIT), which is used to determine the key hydrogeological parameters of the subsurface fractured rock aquifer, namely hydraulic conductivity and storativity. This report further refines the standard test method suggested by the KSRM in 2022 and includes practical field application case conducted in volcanic rock aquifers where this investigation procedure has been applied.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.119-121
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• 2007

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.4
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• pp.133-140
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• 1990

Th. mechanism of hydraulic fracturing in sandy soil is elucidated by investigating the relation among the hydrofracturing pressure($P{_f}^{\prime}$), the confinning pressure(${\sigma}_3^{\prime}$), the tensile strength of gelled sand(${\sigma}_t$), and the permeability of sand(k) through many injection tests on several kind of sand.