• Title/Summary/Keyword: drilling survey

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A Study on Verification of the FRP Grouting Effect using 2D Resistivity Survey and Seismic Refraction Methods (지표물리탐사 기법을 이용한 FRP보강 그라우팅 공법의 보강효과 확인에 관한 사례연구)

  • Park, Jong-Ho;Han, Hyun-Hee;Chae, Hwi-young;Kim, Ik-Hee;Cho, Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.03b
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    • pp.199-206
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    • 2000
  • The grout-effect evaluation of the ground reinforcement technique, which has been widely applied to civil engineering and construction fields, is not established for the guidelines of choosing the efficient evaluation method, and in fact the experts have little effort to determine the reinforcement effect quantitatively. The evaluation of the grout was carried out by experiments on core specimen and drilling, which is impossible to evaluate grout-reinforcement effect quantitatively. This paper presents an example on verification of FRP grout-effect using geophysical prospecting on ground surface, which is 2D resistivity survey that easily visualize survey results with color graphics and seismic refraction method that interprets the subsurface seismic velocity structure.

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Magnetotelluric surveys from mid-mountain area of Jeju Island for evaluating possible structures for deep-seated geothermal energy (심부 지열에너지 개발 가능성 파악을 위한 제주도 증산간 지역에서의 MT 탐사)

  • Lee, Tae-Jong;Lee, Seong-Kon;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.434-437
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    • 2006
  • Though numerous drilling has been performed in Jeju Island for development of ground water, the wells are mostly located along the coast lines or at low altitude area, and can hardly be found on the mid-mountain area. Two-dimensional magnetotelluric (MT) surveys have been carried out to cover the lack of geological Informal ion on the mid-mountain area and to figure out any possible structures or evidences for deep geothermal energy remained. Two-dimensional (2-D) inversion of MT data for four survey lines surrounding the Halla mountain show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsol idated sedimentary layer. And they also show a conductive anomaly extending to more than 2km depth at the central part of each survey lines, which can possibly be related with old volcanic activities during the formation of Halla Mt.. Further seological/geophysical investigations should be followed.

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A Study on the Variation of the Surface and Groundwater Flow System related to the Tunnel Excavation in DONGHAE Mine Area(l)-Concern on Hydrological and Rock Hydraulic Approach (동해신광산 터널굴착공사와 관련된 지표수 및 지하수의 유동변화에 대한 조사연구(l)-수문학 및 암반수리학적 접근을 중심으로)

  • 이희근;전효택;이종운;이대혁;류동우;오석영
    • Tunnel and Underground Space
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    • v.5 no.4
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    • pp.347-362
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    • 1995
  • The purpose of this study was that manage effectively the excavation process of the transport tunnel in DONGHAE mine area by investigating the variationof the surface and groundwater flow system around the tunnel and neighbouring villages. Thus, the effect of excavation and water-prrofing process on the water system has been studied through the naked eye survey of the tunnel and the surface outcrop, joint survey, core drilling, the measurement of the surface water quantity, evapotranspiration and precipitation analysis, rock hydraulics approach, the pressure test of boreholes, the variation of the water level, and finally the numerical analysis. From above approachs, we derived the conclusion that the exhaustion of the surface water was not caused by the tunnel excavation on the groundwater system was minimized by effective water proofing process.

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An Interpretation of Hydrogeologic Structure Using Geophysical Data from Chungwon Area, Chungcheongbuk-Do (물리탐사자료를 이용한 수리지질구조 해석 -충청북도 청원지역)

  • 송성호;정형재;권병두
    • Economic and Environmental Geology
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    • v.33 no.4
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    • pp.283-293
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    • 2000
  • A set of geophysical survey results over an area in Bookil-myun, Chungwon-Gun, Chungcheongbuk-Do is presented; resistivity logging, d.c. sounding, dipole-dipole resistivity, and controlled-source magnetotelluric (CSMT) surveys. These surveys were chosen in this research for the estimation of the basement depth and the delineation of the hydrogeologic structure over the survey area. The results provide an optimal input to a hydrogeologic modeling analysis using the strategies built in GIS software. A total of 14 lines of dipole-dipole resistivity surveys, 25 stations of d.c. sounding and 6 stations of CSMT sounding were performed. In addition 10 boreholes were chosen for resistivity logging to correlate the logs to the surface data. A quantitative information on the hydrogeologic structure over the area is provided by synthesizing the results from various geophysical data and attribute layers are constructed by utilizing a GIS software Arc/ Info. The constructed layers match well to the hydrogeologic structures, which were outlined from the drilling data. The methodology tested and adopted in this study would be useful for providing a more reliable input to the hydrogeologic model setup.

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The Improvement of Tunnel Construction Cost Standards Considering the Site Conditions in Korea (현장실태를 고려한 국내 터널공사 공사비산정기준 개선)

  • Ahn, Bang-Ryul;Lee, Han-Soo;Oh, Jae-Hoon;Song, Tae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.8
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    • pp.26-35
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    • 2020
  • Tunnel construction is an important part of Korean public construction projects. Although the development of various equipment and technologies has led to advances in tunnel construction methods that are implemented on sites, the cost standards related to such works do not yet reflect the realities of the construction sites. A literature review and site surveys were conducted to suggest reasonable cost standards for tunnel work that reflects the realities of the field. First, each item in the cost standards for tunnel work, as established in the Construction Standard Production Rates, were analyzed. The results were compared with the actual costs implemented on tunnel projects. The key items analyzed included those regarding the work cycle time, such as rock classification, profiling survey, drilling speed, and muck-disposal processing equipment combination, as well as the number of people put to tunneling work. Based on the site survey results, improved estimates regarding the cycle time per one tunnel drilling blast, drilling speed of the machine, muck disposal processing equipment combination, and the number of people put to tunneling work were suggested. This study suggests the cost standards that reflect the realities of tunneling sites. The results are expected to help ensure adequate costs for tunnel construction projects.

Application of Electrical Resistivity Tomography Using Single Well in Seawater Intrusion Areas (해수침투지역에서 단일 시추공을 이용한 전기비저항 토모그래피 탐사의 적용성)

  • Song, Sung-Ho
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.369-376
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    • 2007
  • Electrical resistivity tomography was carried out at seawater intrusion monitoring wells located at watershed in coastal areas. It is difficult to identify the characteristics of resistivity near monitoring well in case of using high signalto-noise ratio array due to the high conductivity condition in coastal aquifer although electrical resistivity survey is well adopted to delineate hydrogeological characteristics with the distribution of electrical resistivity. To improve the quality of electrical resistivity survey for two sites with seawater intrusion monitoring wells, inversion with the results of holeto-surface electrical resistivity tomography using single well was executed. The results of inversion for aquifer near wells were verified with the results of drilling log with the informations of fracture, electrical conductivity logging and normal resistivity logging. The inversion for aquifer near one of two wells was also performed at low and high tide with the same electrodes, respectively. From the inversion result, it is possible to obtain the resistivity images with high resolution and to identify the characteristics of aquifer related to seawater intrusion with tidal fluctuation. From this study, it was demonstrated that the hole-to-surface electrical resistivity tomography method accompanied with drilling log, electrical conductivity logging and normal resistivity logging would be useful to delineate the hydrogeological structures near monitoring wells in coastal areas.

Geoscientific Research of Bedrock for HLW Geological Disposal using Deep Borehole (고준위방사성폐기물 심층처분을 위한 심부 시추공을 활용한 암반의 지구과학적 조사 )

  • Dae-Sung, Cheon;Won-Kyong, Song;You Hong, Kihm;Seungbeom, Choi;Seong Kon, Lee;Sung Pil, Hyun;Heejun, Suk
    • Tunnel and Underground Space
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    • v.32 no.6
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    • pp.435-450
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    • 2022
  • In step-by-step site selection for geological disposal of high-level radioactive waste, parameters necessary for site selection will be acquired through deep drilling surveys from the basic survey stage. Unlike site investigations of rock mass structures such as tunnels and underground oil storage facilities, those related to the geological disposal of high-level radioactive waste are not only conducted in relatively deep depths, but also require a high level of quality control. In this report, based on the 750 m depth drilling experience conducted to acquire the parameters necessary for deep geological disposal, the methodology for deep drilling and the geology, geophysics, geochemistry, hydrogeology and rock mechanics obtained before, during, and after deep drilling are discussed. The procedures for multidisciplinary geoscientific investigations were briefly described. Regarding in-situ stress, one of the key evaluation parameter in the field of rock engineering, foreign and domestic cases related to the geological disposal of high-level radioactive waste were presented, and variations with depth were presented, and matters to be considered or agonized in acquiring evaluation parameters were mentioned.

A Study on Application of Seasonal Thermal Storage System in the Alluvial Aquifer Area (충적대수층 지역에서의 계간축열 지열냉난방시스템 적용 연구)

  • Park, Sungmin;Hwang, Kisup;Mon, Jongphil;Min, Dongmin
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.14 no.3
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    • pp.1-7
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    • 2018
  • In this paper, we designed a seasonal geothermal storage system and studied the applicability in the alluvial aquifer. We conducted a basic survey to apply this system to greenhouses actually operated in the Geum river basin alluvial aquifer. After choosing a potential area through electrical resistivity survey, the system parameters were set using drilling survey and pumping test result. We installed a system based on the factors, and operated for about 9 months. As a result, high temperature water(injection temperature $30^{\circ}C$) was stored at 22.5 Mcal ($1,609m^3$) for 3 months in cooling operation and 125 Mcal ($16,960m^3$) of low temperature water (injection temperature $7^{\circ}C$) were stored for 6 months in the remaining heating operation.

An integrated studies for salt-water intrusion in Yeonggwang-gun, Korea

  • Hwang Seho;Chi Sejung;Lee Won-suk;Shin Jehyun;Park Inhwa;Huh Dae-Gee;Lee Sang-kyu
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.455-458
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    • 2003
  • A combination of drilling, hydrogeochemical survey, geophysical survey and the numerical modelling for the flow and transport of groundwater was performed to evaluate the seawater intrusion in Baeksu-eup, Yeonggwang-gun, Korea. The survey area extends to over 24 $km^2$. Twelve wells were also drilled for the collection of geologic, geochemical, hydrologic, and geophysical logging data to delineate the degree and vertical extent of seawater intrusion. To evaluate and map the salinity in a coastal aquifer, geophysical data and hydrogeochemical results were used. Layer parameters derived from VES data, various in situ physical properties from geophysical well loggings, and the estimated equivalent NaCl concentration were used as the useful input parameters for the numerical simulation with density-dependent flow. Our multidisciplinary approach for evaluating the seawater intrusion can be considered as a valuable attempt to enhancing the utilization of various data and the reliability of numerical ground modelling.

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3D Resistivity Survey at a Collapsed Tunnel Site (붕락 터널에서의 3차원 전기비저항 탐사)

  • Cho, In-Ky;Kim, Ki-Seog;Lee, Keun-Soo
    • Geophysics and Geophysical Exploration
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    • v.18 no.1
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    • pp.14-20
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    • 2015
  • Three-dimensional (3D) resistivity method is an effective tool in the engineering site survey because it can provide a 3D resistivity distribution of the site. In this study, we tried to find out faults, fractures and coal seams that can cause the collapse of the tunnel. We carried out 2D resistivity survey along 5 parallel lines and 11 cross lines and merged all the apparent resistivity data for 3D inversion. Finally, from the 3D resistivity image and drilling data we presented the 3D distribution of faults, fractures and coal seams that are considered the main cause of the tunnel collapse.