• Economic and Environmental Geology
• /
• v.56 no.3
• /
• pp.311-330
• /
• 2023

Development of Carbon Capture and Storage (CCS) technique is becoming increasingly important as a method to mitigate the strengthening effects of global warming, generated from the unprecedented increase in released anthropogenic CO₂. In the recent years, the characteristics of basaltic rocks (i.e., large volume, high reactivity and surplus of cation components) have been recognized to be potentially favorable in facilitation of CCS; based on this, research on utilization of basaltic formations for underground CO₂ storage is currently ongoing in various fields. This study investigated the feasibility of underground storage of CO₂ in basalt, based on the examination of the CO₂ storage mechanisms in subsurface, assessment of basalt characteristics, and review of the global research on basaltic CO₂ storage. The global research examined were classified into experimental/modeling/field demonstration, based on the methods utilized. Experimental conditions used in research demonstrated temperatures ranging from 20 to 250 ℃, pressure ranging from 0.1 to 30 MPa, and the rock-fluid reaction time ranging from several hours to four years. Modeling research on basalt involved construction of models similar to the potential storage sites, with examination of changes in fluid dynamics and geochemical factors before and after CO₂-fluid injection. The investigation demonstrated that basalt has large potential for CO₂ storage, along with capacity for rapid mineralization reactions; these factors lessens the environmental constraints (i.e., temperature, pressure, and geological structures) generally required for CO₂ storage. The success of major field demonstration projects, the CarbFix project and the Wallula project, indicate that basalt is promising geological formation to facilitate CCS. However, usage of basalt as storage formation requires additional conditions which must be carefully considered - mineralization mechanism can vary significantly depending on factors such as the basalt composition and injection zone properties: for instance, precipitation of carbonate and silicate minerals can reduce the injectivity into the formation. In addition, there is a risk of polluting the subsurface environment due to the combination of pressure increase and induced rock-CO₂-fluid reactions upon injection. As dissolution of CO₂ into fluids is required prior to injection, monitoring techniques different from conventional methods are needed. Hence, in order to facilitate efficient and stable underground storage of CO₂ in basalt, it is necessary to select a suitable storage formation, accumulate various database of the field, and conduct systematic research utilizing experiments/modeling/field studies to develop comprehensive understanding of the potential storage site.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.5
• /
• pp.395-409
• /
• 2022

To overcome the limitation of conventional rock excavation methods, the excavation with abrasive waterjet has been actively developed. The abrasive waterjet excavation method has the effect of reducing blasting vibration and enhancing the excavation efficiency by forming a continuous free surface on the rock. However, the waterjet cutting performance varies with rock fracturing characteristics. Thus, it is necessary to analyze the cutting performance for various rocks in order to effectively utilize the waterjet excavation. In this study, cutting experiments with the high pressure waterjet system were performed for basalt and granite specimens. Water pressure, standoff distance, and traverse speed were determined as effective parameters for the abrasive waterjet cutting. The cutting depth and width of basalt specimens were analyzed to compare with granite results. The averaged cutting depth of basalt was shown in 41% deeper than granite; in addition, the averaged cutting width of basalt was formed by 18.5% narrower than granite. The results of this study are expected to be useful basic data for applying rock excavation site with low strength and high porosity such as basalt.

• Journal of the Korean Geosynthetics Society
• /
• v.14 no.4
• /
• pp.129-137
• /
• 2015

Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. One of the most obvious applications of the pressuremeter test is the solution of the problem of laterally loaded piles. A hyperbolic non-linear p-y criterion for rock is developed in this study that can be used in LPILE program, to predict the deflection, moment, and shear reponses of a shaft under the applied lateral loads. Finally, a comparison between the predicted and measured response at two different sites is shown to give an idea of the accuracy of the IFP method.

• Food preservation and processing industry
• /
• v.14 no.2
• /
• pp.70-81
• /
• 2015

• Journal of Naturopathy
• /
• v.11 no.1
• /
• pp.18-30
• /
• 2022

Background: It was to develop an air purification system (APS) using an underground air purification layer to verify the effect of basalt forest's underground air (sumgol) on a volcanic Jeju. Finally, it is necessary to analyze these purified air components and their usefulness to the human body in an air experience center. Purpose: It was to collect basalt forest air, analyze its composition, and explore its effect on the human body. Methods: We APS devices installed at four points in the Papaville area of Jeju. The air discharged from the APS was collected and analyzed the recycling components. An installed experience room filled with negative ions is about 5,000 ions/m³. After allowing the participants to stay for 60 to 120 minutes, we investigated the state of blood vessels. Results: In the analysis of the underground air, the O₂ concentration was 21.18%, which was higher than the average oxygen concentration of 20.94% in the atmosphere. However, Formaldehyde was not detected, and the CO₂ was 419 ppm, which was lower than that of indoor air. The PM2.5 concentration was less than 24 ㎍/m³ and detected anions over 5.000 /m³. The experiencer's vascular states improved, and the increase in pulse rate and stress relief were high. Conclusions: The valuable ingredients identified by analyzing the air were precious for natural healing. The experience results showed that it effectively improved the pulse rate, blood vessels, and stress. These conditions may be highly beneficial as a new area for expanding the basalt lava forest in the Jeju area into the natural healing and wellness industry.

• Economic and Environmental Geology
• /
• v.49 no.6
• /
• pp.479-490
• /
• 2016

Seabed drilling system has recently been used to drill seafloor mineral resources. This case report highlights the procedure and result of sea-trial of seabed drilling system at off-shore of Japan on March, 2016 as well as briefs an international-technical trend of seabed drilling system. In case of having less than 100 m drill depth, seabed drilling system is favorable for seafloor mineral deposits which are mostly distributed within a narrow district and situated between 1000~3000 m water depth, compared with vessel-mounted drilling system. The system is featured by the remotely-operated drill gear, which has top drives, drill strings and mud system on it. The core samples are generally recovered to ship with seabed driller after a dive. In this sea-trail, recovery rate of core samples averagely shows about 55% and the recovered rocks mostly correspond to fresh and/or weak-altered basalt. In case of drilling hydrothermal ore deposit, the recovery rate would be lower than 55% because of the fragile nature of ores. Alternatively it is used to collect cutting chips through riser or bins in order to increase the recovery rates. Recently a reverse circulation method is taken considered to acquire the better cutting-chips. Three-leg type outrigger system and four-leg type leveling system are the competing landing-instruments of seabed drill system. However the landing efficiency using these gears has to be further monitored due to lack of case reports.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.1241-1245
• /
• 2006

절 성토사면에 구조물을 설치할 경우 가장 중요하게 고려되어야 하는 점은 사면의 안정성 여부이다. 특히, 절 성토사면에 설치된 구조물이 붕괴되는 가장 큰 원인은 뒷채움재 내에 존재하는 수압의 영향이라는 것을 우리는 이미 많은 연구와 경험을 통해 알고 있다. 만일 지하수위가 존재하는 상태에서 단시간에 발생되는 집중호우로 인해 수위가 갑자기 상승하였을 경우, 구조물을 통해 전혀 배수되지 않는다면 절 성토사면의 안정성은 급격히 저하될 것이다. 이러한 사면의 배수압을 소산시킬 수 있는 공법은 여러 가지가 있으나, 본 연구에서는 특히 제주도의 지역적 특성을 고려하여 화산석을 채움재로 사용한 Mattress/Filter를 절 성토사면에 설치함으로써 배수압을 소산시킬 수 있는 방법을 연구하였다. Mattress/Filter는 제방 또는 절 성토사면의 파괴와 침식을 방지하기 위해 사면에 설치하는 육각형의 철망구조로서 유연성, 다공성, 배수성 및 식생성과 같은 특징이 있으며, 콘크리트 구조물과 달리 별도의 배수시설을 필요로 하지 않는 장점이 있다. 또한 본 연구에 사용된 Mattress/Filter의 채움재인 화산석은 현재 제주도 지역에 방대하게 분포되어 있다. 특히 현무암은 제주도 암석 전체의 90%이상을 차지하고 있으며, 투수성이 매우 큰 암석이다. 현무암의 공극률은 그 종류에 따라 $0.02{\sim}0.36$의 범위로 나타난다. 특히, 표선리현무암의 경우 평균 공극률이 0.23으로 나타나 모래의 공극률인 $0.3{\sim}0.8$에 비교하여 볼 때, 연구에 사용된 재료는 아주 우수한 투수성을 가진 것으로 판명된다. 또한 현무암의 경우 암석의 겉 표면이 미세한 다공질 조직으로 이루어져 있다. 따라서 암석자체에 물이 정체될 수 있어 구조물을 통해 배수될 때 암석이 머금고 있는 물로 인해 추가적으로 발생하는 중력은 다른 재료가 가지지 못한 화산석의 또 다른 장점이라 할 수 있다.서는 자료변환 및 가공이 필요하다. 즉, 각 상습침수지구에 필요한 지형도는 국립지리원에서 제작된 1:5,000 수치지형도가 있으나 이는 자료가 방대하고 상습침수지구에 필요하지 않은 자료들을 많이 포함하고 있으므로 상습침수지구의 데이터를 인터넷을 통해 서비스하기 위해서는 많은 불필요한 레이어의 삭제, 서비스 속도를 고려한 데이터의 일반화작업, 지도의 축소.확대 등 자료제공 방식에 따른 작업 그리고 가시성을 고려한 심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주식시장에 적합한 거래전략은 반전거래전략이고, 이 전략의 유용성은 투자자가 설정한 투자기간보다 더욱 긴 분석기간의 주식가격정보에 의하여 최대한 발휘될 수 있음을 확인하였다.(M1), 무역적자의 폭, 산업

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.1
• /
• pp.1-10
• /
• 2016

Recently, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. Jeju island has optimum condition for constructing a wind energy farm. Unlike the mainland, Jeju island has stratified structure distribution between rock layers sediments due to volcanic activation. In these case, it can be occur engineering problems in whole structures as well as the safety of foundation as the thickness and distribution of sediment under top rock layer can not support sufficiently the structure. In this study, field lateral load test of the pile for analyzing lateral behavior of the offshore wind turbine which is embedded in basalt. After calculating the subgrade resistance and the horizontal deflection from the measured strain to derive p-y curve from the lateral load test results, the subgrade resistance amplifies the error in the process of differentiation and the error of piecewise polynomial curve fitting is the smallest. In order to calculate the horizontal deflection from the measured strain, the six-order polynomial was used.

• Journal of the Speleological Society of Korea
• /
• v.17 no.18
• /
• pp.13-105
• /
• 1988

만장굴은 북제주군 구좌면 동금영리 지역에 있는 금영사굴을 포함하여 세계 최대의 화산 동굴 시스템을 형성하고 있는 화산동굴로 표선리 현무암층에 속한다. 만장굴이 처음으로 알려지게 된 것은 1947년 부종휴가 현재의 제2입구를 발견하면서 부터이다. 그러나 본격적인 학술적 조사가 시작된 것은 1977년 제1차 한ㆍ일 합동동굴조사에서 부터이다. 그 후 1986년에 이르기가지 6차에 걸친 구제적인 합동조사가 실시되었다.(한국측 단장 홍시환, 일본측 단장 소천효덕)특히 1981년 1월의 제 2 차 한ㆍ일 합동조사결과는 만장굴이 세계 제일의 동굴계로 확인되었다. 또한 1982년 2월에 실시된 제 4 차 한ㆍ일 하동조사에서는 5개의 용암구(Lava Ball)등 새로운 특수지형이 발견되었다. 이보다 앞서 실시된 1977년의 제 1차 조사에서는 만장굴 6,978m, 금영사굴 600m 임이 조사되었다.(중략)

• Journal of the Korean association of regional geographers
• /
• v.13 no.1
• /
• pp.32-42
• /
• 2007

In Sagye coast of Andeok-myeon, southwestern Jeju, shore platform of noncohesive Hamori Formation, marine terrace deposit of round gravels, coastal dune composed of shell sand and volcanic sand, and back lake are linked closely with each other. In this paper, the formation process of Sagye coastal geomorphic system analysed by using OSL dating method is as follows: Firstly, Hamori Formation is a horizontal stratum filed up of tuff reworked by submarine volcanic eruption during 3$\sim$7.6 ka BP. Hollow at the boundary between Hamori Formation' flat and Kwangheak Basalt's gentle slope become a back lake when block is appeared over the sea level by uplift. Secondly, while Hamori Formation was laid below sea level, gravels which had been broken and abraded at southwestern rocky coast composed of Kwangheak basalt or been transported through the small stream from adjacent hillslope were deposited in rapid flow environment. Thirdly, deposition of round gravels was ceased by earth uplift, and shore platform was constructed by abrasion process of energy of swash moving forward. As altitude of shore platform is equal to high tidal level of spring tide, compared it with present high tidal level of study area, earth is uplifted about 105m since shore platform was formed. Fourthly, much sandy sediments transported from offshore bottom covered shore platforms and marine terrace deposits. Lighter sediments among sandy sediments was blown to back, formed secondary sand dune since about 500 year.