논문 : 실내 모형과 현장 충적층에서 지하투과레이더를 이용한 지하수면 추정

김병우 ( Byung Woo Kim ),김형수 ( Hyoung Soo Kim ),최두형 ( Doo Houng Choi ),고용권 ( Yong Kwon Koh ) 대한지질공학회 2013 지질공학 Vol.23 No.3

지하수면과 불포화대의 수분 포화도가 지하투과레이더(GPR) 신호에 미치는 영향을 연구하기 위하여 실내 토조와 충적층 현장에서 GPR 조사를 수행하였다. 실내의 모래 채움 토조 실험에서, 지하수위를 변화시키기 위해 물을 탱크 바닥에 설치된 밸브를 통해 주입하고 배수시켰다. 지하수위와 수분포화도를 추정하기 위하여 모래 채움 토조에서 GPR 수직반사법(이후, VRP) 자료가 획득되었다. 실내 모래 채움 토조에서 획득한 GPR 신호는, 지하수위는 물론 함수율 변화에도 민감하게 반응함을 보여준다. 불포화대에서 GPR 속도는 함수율 변화에 따라 크게 조절되며, 주시 시간의 증가는 포화도의 증가로 해석된다. 함안군 이룡리 낙동강변 충적층에서 220m에 달하는 VRP 조사가, 지하수위를 추정하기 위하여 수행되었다. 현장 조사 결과, 포화 조건에서 GPR 신호의 첫 번째 반사면은 모관 상승에 의한 경계부를 지시하며, 실제 지하수면과는 차이가 있음을 지시한다. 보다 정확한 지하수위를 추정하기 위하여, Well-3호공 주변에서 중앙공심점(common mid-point, 이후, CMP) 방식 GPR 조사를 수행하였다. 그 결과, 모관 상승 경계부와 지하수면 속도를 구하였고, 이는 보다 상세한 지하수면과 심도별 포화도 정보를 제공하였다. 지하수면과 포화도 정보를 포함하는 GPR 조사 결과는 통기대의 현장 수리 지질학적 특성 조사에 유용한 수단이다. Ground penetrating radar (GPR) surveys were conducted in a sand tank model in a laboratory and at an alluvial field site to detect the groundwater table and to investigate the influence of saturation on GPR response in the unsaturated zone. In the sand tank model, the groundwater table and saturation in the sand layer were altered by injecting water, which was then drained by a valve inserted into the bottom of the tank. GPR vertical reflection profile (VRP) data were obtained in the sand tank model for rising and lowering of the groundwater table to estimate the groundwater table and saturation, Results of the lab-scale model provide informatiou on the sensitivity of GPR signals to changes in the water content and in the groundwater table. GPR wave velocities in the vadose zone are controlled mainly by variations in water content (increased travel time is interpreted as an increase in saturation), At the field site. VRP data were collected to a depth of 220 m to estimate the groundwater table at an alluvial site near the Nakdong river at Iryoug-ri. Haman-gun, South Korea. Results of the field survey indicate that nuder saturated conditions, the first reflector of the GPR is indicative of the capillary fringe and not the actual groundwater table. To measre the groundwater table more accurately. we performed a GPR survey using the common mid-point (CMP) method in the vicinity of well-3, and Sunk a well to check the groundwater table. The resultant CMP data revealed reflective events from the capillary fringe and groundwater table showing hyperbolic patterns. The normal moveont correction was applied to evaluate the velocity of the GPR, which improved the accuracy of saturation and groundwater table information at depth. The GPR results show that the saturation information, including the groundwater table. is useful in assessing the hydrogeologic properties of the vadose zone in the field.

해안대수층 지하수흐름의 특성 : 실내 실험연구 LABORATORY EXPERIMENTS

박남식,김진후,나겐드라 쿠마,홍성훈,김현도 東亞大學校建設技術硏究所 2004 硏究論文集 Vol.28 No.1

Experiments were conducted using laboratory models to study salt water intrusion phenomena in coastal aquifers. Two models filled with sand were used. The smaller model could produce steady-state cross-sectional flow in a reasonably short time. The bigger model produced a more interesting three-dimensional flow field compare to the smaller one, but it also took much more time to reach steady states and posed difficulties in observing results. A cross-sectional model was used to investigate 'freshwater lens'phenomena. A few pumping scenarios were tested. Contamination of the well with excessive withdrawal was observed. The effectiveness of a scavenger well was studied. The bigger model was used to study the steady-state lateral intrusion problems. Various attempts were made to measure the interface position in the sand.

Experimental Study on Indentation Behavior of U-Type Section Steel Piling

김진우,김태훈,박해용,김태수 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

Steel sheet piles are known for their straightforward assembly and construction, making them a popular choice that is often repurposed for other building projects once disassembled. Regarding the re-use of these steel sheet piles, understanding their behavior during penetration into the soil becomes pivotal. This study focuses on assessing the potential reusability of steel sheet piles as they penetrate into the soil. A laboratory-scale experiment involving the insertion of a steel sheet pile into a sand-fi lled tank was conducted. The experimental variables were the relative density of the soil, length of the steel sheet pile, and penetration method. The behavior of the sheet pile was analyzed, including the force-insertion length relationship and the strain of deformation occurring locally in the sheet pile. The results indicated that higher relative soil densities led to increased strain within the sheet pile. The strain values remained within the elastic range during the experiment. Notably, when interpenetrating the steel pile with a coupling mating joint test specimen, the strain showed an inverted mountainshaped distribution within the interlock.

Comparative studies of novel biooxidation process to low-grade sulphide gold ores

Ahn Junmo,Wu Jiajia,Lee Jaeheon 한국자원공학회 2022 Geosystem engineering Vol.25 No.4

The Sand Farming is one of novel biooxidation processes suitable for sulphide oxidation of lowgrade refractory gold ores. It has been previously proven to be feasible and more efficient compared to other conventional sulphide oxidation processes. In this study, the Sand Farming was compared with conventional tank biooxidation to investigate biooxidation behaviors on ores with different mineralogy and compare the ultimate gold recovery. Ore samples were tested for Sand Farming biooxidation. Conventional tank biooxidation was also compared as the baseline. After each biooxidation was completed, cyanidation was conducted for gold extraction. The Sand Farming achieved the gold recovery of 75% from high grade with higher sulphur content sample (Sample A) and 68% from low grade with lower sulphur content sample (Sample B), slightly lower than tank biooxidation of 83% and 85%, respectively. Sand Farming can be an alternative to several sulphide oxidation processes with better overall economics.

부패조와 모래트렌치를 이용한 소규모 오수 처리

박영식 한국환경보건학회 2003 한국환경보건학회지 Vol.29 No.1

This study was carried out to treat sewage using sand trench combined with septic tank process in rural areas. In order to find optimum parameters, design and operation mode was changed from Run 1 to Run 4. In order to facilitate nitrification and T-P removal, diffuser and iron plate was installed in the 3rd trench of Run 2 period. The septic tank played a role as pre-application process of sand trench system. The removal efficiencies of COD, NH$_4$-N, T-P at steady state were 94.6%, 87.9% and 54.5%, respectively. Addition of diffuser and iron plate in the 3rd trench has increased the removal efficiencies of the NIL-N and T-P. In this system, denitrification were not occurred because of the high DO.

작업자 안전을 위한 FRP 정화조 제조의 자동화 시스템 개발

박강,한영근,박주식,강경식 대한안전경영과학회 2004 대한안전경영과학회지 Vol.6 No.1

The processes of manufacturing FRP sewage disposal tanks are very dangerous and hazardous jobs for workers because of large size and heavy weight of the tank, toxic fiberglass dust, nasty smell, and dangerous tools such as hand-grinders. This paper introduces an automatic manufacturing system of the FRP sewage disposal tank to enhance the safety of workers. The system consists of 3 components: the FRP body rotation jig, the automatic manhole cutting machine, the automatic sanding processing machine. The safety of workers and working environment are greatly improved, because the dangerous jobs are automatized and the toxic fiberglass dust is automatically collected. Also, the productivity is greatly improved and the cost is reduced.

토조 및 수치모형을 이용한 개방형 지중 열교환 시스템 모의

이성순(Lee, Seong-Sun),배광옥(Bae, Gwang-Ok),이강근(Lee, Kang-Kun) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.11

Understanding the thermohydraulic processes in the aquifer is necessary for a proper design of the aquifer thermal energy utilization system under given conditions. Experimental and numerical test were accomplished to evaluate the relationship between the geothermal heat exchanger operation and hydrogeological conditions in the open-loop geothermal system. Sand tank experiments were designed to investigate the open-loop geothermal system. Water injection and extract ion system as open-loop borehole heat exchanger was applied to observe the temperature changes in time at injection well, extraction well and ambient groundwater. The thermohydraulic transfer for heat storage was simulated using FEFLOW for two cases of extraction and injection phase operation in sand tank model. As one case, the movement of the thermal plume was simulated with variable locations of injection and extraction well. As another case, the simulation was performed with fixed location of injection and extraction well. The simulation and experimental results showed that the temperature distribution depends highly on the injected water temperature and the length of injection time and the groundwater flow and pumping rate sensitively affect the heat transfer.

여과기가 내장된 농어촌 생활용수용 자동화 물탱크 장치 개발

김봉석 한국기계기술학회 2016 한국기계기술학회 학술대회논문집 Vol.2016 No.05

The purpose of this study is to develop the automatic water wank for rural living water with a built-in filter device. For this purpose, the author carrying out the design and production of devices such as a stacked plate filter, automatic water tank and water purification equipment, main control system and solenoid valve, solar cell, battery, water gauge, flowmeter and pump, etc. As a result, the author obtained very good results which satisfy all the research and development objectives planned. In addition, the water quality test results received, it is determined that the water is suitable for rural living water standards of the developed prototype.

하상여과의 집수관 모형에서 잔류수두와 유입율 분포에 관한 실험연구

안규홍(Kyu Hong Ahn),문형준(Hyung Joon Moon),김경수(Kyung Soo Kim),김승현(Seung Hyun Kim) 大韓環境工學會 2005 대한환경공학회지 Vol.27 No.12