• Title/Summary/Keyword: Packer

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The Development of Straddle Packer Hydraulic Testing Equipment to Characterize Permeability in Deep Boreholes (장심도 시추공 정밀수리시험 장비 구축)

  • Kim, Kyung-Su;Park, Kyung-Woo;Ji, Sung-Hoon
    • The Journal of Engineering Geology
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    • v.20 no.2
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    • pp.213-220
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    • 2010
  • The permeability characterization on the natural barrier for deep geological disposal of radioactive waste is very critical to evaluate total safety and performance assessment of disposal site. However, the confidence level in using previous hydraulic testing equipments consist of simple components to estimate rock mass permeability is not high enough to reflect in situ condition. The purpose of this research is to establish an advanced hydraulic testing equipment, which is applicable to deep borehole (up to 1,000 m), through the improvement of technical problems of previous packer systems. Especially, the straddle packer hydraulic testing equipment was designed to adopt both the hydraulic downhole shut-in valve(H-DHSIV) to minimize the wellbore storage effect and the real time data acquisition system to measure the pressure changes of test interval including its upper and lower parts. The results from this research lead to not only improve current technical level in the field of hydraulic testing but also provide important information to radioactive waste disposal technology development and site characterization project.

Groundwater Flow Analysis in Fractured Rocks Using Zonal Pumping Tests and Water Quality Logs (구간양수시험과 수질검층자료에 의한 균열암반내 지하수 유동 분석)

  • Hamm, Se-Yeong;Sung, Ig-Hwan;Lee, Byeong-Dae;Jang, Seong;Cheong, Jae-Yeol;Lee, Jeong-Hwan
    • The Journal of Engineering Geology
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    • v.16 no.4 s.50
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    • pp.411-427
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    • 2006
  • This study aimed to recognize characteristics of groundwater flow in fractured bedrocks based on zonal pump-ing tests, slug tests, water quality logs and borehole TV camera logs conducted on two boreholes (NJ-11 and SJ-8) in the city of Naju. Especially, the zonal pumping tests using sin91e Packer were executed to reveal groundwater flow characteristics in the fractured bedrocks with depth. On borehole NJ-11, the zonal pumping tests resulted in a flow dimension of 1.6 with a packer depth of 56.9 meters. It also resulted in lower flow dimensions as moving to shallower packer depths, reaching a flow dimension of 1 at a 24 meter packer depth. This fact indicates that uniform permissive fractures take place in deeper zones at the borehole. On borehole SJ-8, a flow dimension of 1.7 was determined at the deepest packer level (50 m). Next, a dimension of 1.8 was obtained at 32 meters of packer depth, and lastly a dimension of 1.4 at 19 meters of packer depth. The variation of flow dimension with different packer depths is interpreted by the variability of permissive fractures with depth. Zonal pumping tests led to the utilization of the Moench (1984) dual-porosity model because hydraulic characteristics in the test holes were most suitable to the fractured bedrocks. Water quality logs displayed a tendency to increase geothermal temperature, to increase pH and to decrease dissolved oxygen. In addition, there was an increasing tendency towards electrical conductance and a decreasing tendency towards dissolved oxygen at most fracture zones.

Evaluation of Injection Property on the Crack Repair Method by Installing the Packer with Right Angle Drill Type in RC Structure

  • Ko, Jinsoo;Lee, Sungbok;Kim, Byungyun;Seo, Cheho
    • Architectural research
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    • v.11 no.2
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    • pp.27-34
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    • 2009
  • The purpose of this study is to investigate the problem of crack repair materials and methods in existing concrete structure and to propose the effective injection method on crack repair by packer type. The result of this study is as follows. It is investigated that the crack width in the inner matrix of concrete structure is decreased about 30-40% than that in the surface of the concrete structure. Also it is showed that the possibility which could be monolithic with injection part became higher if the injection part is installed near to surface of concrete on the punching method to vertical direction against crack area. The injection of repair material can be poured smoothly under about $10N/mm^2$ pressure on the condition that cracks are monolithic with injection part without dust by drill. The method which is effective injection for a repair material is the punching method in compliance with coredrill. But, the research continuously is necessary about minimum injection pressure.

Evaluation of Injection Property on the Crack Repair Method by installing the packer with Right Angle Drill Type in RC Structure (직각천공방식으로 패커를 설치한 콘크리트 균열보수공법의 보수재 주입특성에 관한 연구)

  • Ko Jin-Soo;Lee Sung-Bok;Seo Che-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.6 no.2 s.20
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    • pp.91-98
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    • 2006
  • The purpose of this study is to investigate the problem of crack repair materials and methods in existing concrete structure and to propose the effective injection method on crack repair by packer type. The result of this study is as follows. It is investigated that the crack width in the inner matrix of concrete structure is decreased about 30-40% than that in the sulfate of the concrete structure. Also it is showed that the possibility which could be monolithic with injection part became higher if the injection part if installed near to surface of concrete on the punching method to vertical direction against crack area. The injection of repair material can be poured smoothly under about $10N/mm^2$ pressure on the condition that cracks are monolithic with injection part without dust by drill. The effective method to pour the injection repair material is the punching method by coredrill but several research to minimize injection pressure should be continually.

Estimation from Field Tests of the Excavation Efficiency of an Improved Hydraulic Rock Splitting System (현장실험을 통한 개선된 수압암반절개시스템의 굴착 효율성 평가)

  • Park, Jong Oh;Woo, Ik
    • The Journal of Engineering Geology
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    • v.31 no.4
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    • pp.719-730
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    • 2021
  • An improved packer and injection system was developed to improve the efficiency of excavation by hydraulic rock splitting by reducing vibration and noise. Field testing of the system found hydraulic fractures limited in expansion and extension due to the loss of injection pressure by leackage from the cracks, and then the single packer applied to injection hole allowed to produce a sufficient tensile displacement for rock excavation. Numerical analysis based on the field test data could explain the development of cracks in the field experiments.

Development of the Compressed Packer Grouting Device for Preventing the Inflow of Polluted Groundwater (오염지하수 유입방지를 위한 압축패커 그라우팅 장치 개발)

  • Cho, Heuy-Nam;Choi, Sang-Il
    • The Journal of Engineering Geology
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    • v.19 no.4
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    • pp.433-439
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    • 2009
  • The compressed packer device is designed to improve the underground contamination prevention facilities of ground water wells. As for the device, the installation is simple because of the safety lock device and the compression of the casing are simple the installation is simple. There is no leakage of ground water because the pressure resistance with $4.5\;kg/cm^2$ makes it equipped with the watertightness The single casing is installed and the reaming for grouting is possible with 300 mm excavation so that installation cost can be saved. Silicon rubber is used for the compressed packer so that the extension rate is 590%. In terms of environmental pollution, it is an environmental friendly product which does not contain harmful ingredients such as Pb, Cd, and phenol. below the standard or undetectable level Furthermore, the installation costs are 35 to 62% or lower than the conventional grouting construction method and are 87% or lower than the expansion packer construction method, the new environmental technology No.47 Also, the device is designed to meet the relevant regulations such as Rules on Preserving the Ground Water Quality, The Standard on Jeju Island Ground Water Development and Facility Installation and Management, and The Plan and Guideline on Operating and Managing the Small-Scale Tap Water Facilities of Ministry of Environment and Ministry of Food, Agriculture, Forestry and Fisheries.