• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.141-155
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• 2018

Recently, the number of ground subsidence resulting from underground cavity has been increased. Accordingly, the importance of restoration of stress release zone around the underground cavity has been emphasized. The stress release zone is composed of low density soils having extremely low stiffness and degree of compaction, which can lead to additional cavity expansion and collapse of overlying ground. Therefore, in this study, the suitability of restoration method of underground cavity using expansive material for reinforcement of stress release zone around the cavity is verified. The basic physical properties and expansion characteristics of the expansive material were examined. The experiment equipment capable simulating of stress release zone was developed and is used to investigate the effect of expanding material on stress release zone. The stress release zone was simulated using the spring in numerical analysis. The factors of the volume ratio of the underground cavity to the expansion material, the degree of stress relaxation, and the shape of the cavity were varied in numerical simulations, and the behavior of stress release zone was analyzed based on the numerical analysis results. Analysis variables are factors that affect each other. Also, filling of underground cavity and capacity of restoration of stress release zone were confirmed when the expansive material was inserted into underground cavity.

• Proceedings of the Speleological Society Conference
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• 1995.08a
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• pp.89-89
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• 1995

1. 한반도의 중부동해안에 면하고 있는 항구도시 2. 시화로는 매화꽃, 시목으로는 은행나무, 시조로는 갈매기를 지정하고 있는 해항도시 3. 어항이었던 묵호항, 산업항인 북평항이 통합되어 이룩된 동해시 4. 한반도 동해안에서는 손꼽을 수 있는 해항도시의 하나 5. 남북으로 통하는 동해연안의 간선도로 따라 발전하고 있는 구릉 사면과 연안평야의 발달 6. 충북 아시아권역의 해항들과 자매결연 추진중 7. 온대습윤기후구에 속하며 연평균기온 섭씨12도, 연강수량 1,220mm 겨울에 따뜻하고 연중 서풍이 많으나 여름에는 남동풍이 많은 기후. 8. 석회암이 산재하는 지역이므로 식생은 하생식물이 적은 잡목림상을 이루고 있음. 9. 주변에 자연 풍치자원과 해수욕장 그밖에 민속 자원이 산재하는 지역. 10. 오래전부터 지하자원의 보고로 각종 광산자원이 이곳에 분포. 11. 쌍용시멘트, 동부산업합금철공업 이외에도 북평 공업단지가 건설 중. 12. 해륙교통 입지는 물론, 산업입지 그리고 관광입지로도 유망한 해항. 13. 접안 시설과 하역 능력을 계속 확장시키고 있는 국제항구도시.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.120-121
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• 2001

The purpose of this study is to investigate concrete flaw using seismic first arrival and various inversion method. Seismic wave propagation was calculated using finite element method in theoretical modelling and tomogram was made using various inversion methods in theoretical and experimental modelling. Five steps of seismic first arrival were selected from FEM results and these data were used to calculate seismic velocity section. According to the results, exact seismic first arrival picking method was proposed and experimental modelling was conducted.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.171-174
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• 2002

지구적 차원의 물부족 현상은 우리에게도 심각한 사회적 문제로 대두되고 있으며, 이에 대처하기 위한 방안의 하나로 지표수-지하수 연계이용이 거론되고 있다. 지표수와 지하수 연계이용은 유역의 지표 및 지하수자원을 수문학적 순환 사이클의 통합적 관점에서 파악하는 것으로부터 시작한다. 본 연구는 국내에서 지금까지 이렇다 할 사례가 없는 지표수-지하수 연계이용의 첫 단계로서 연계이용 가능지역을 선정하기 위한 체계적인 적지분석 방법론에 관한 것이다. 복잡한 의사결정 문제를 계층적으로 나누어 분석하는 기법(AHP)이 채택되었고, 분석에 필요한 의사결정인자가 도출되었다. 각 인자의 상대적 중요도가 정량화 된 후, 이를 바탕으로 특정 지역의 지표수-지하수 연계이용 적합도가 산정될 수 있다. 개발된 방법론을 국내 두 개 지역에 적용하여 그 적용성을 예시하였다 개발된 방법론에 의한 적합도 분석은 중앙정부나 지자체가 특정 지역의 연계이용 사업의 추진과 관련된 의사결정을 내릴 수 있도록 판단근거를 제공할 것이며, 지역 간 연계이용 우선순위를 평가하는데도 활용될 수 있을 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.141-143
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• 2014

스마트빌딩에서는 시설물에 대한 효과적인 관리체계 및 안전관리체계를 구축하는 것이 매우 중요하다. 지하 매설관의 경우에는 유속, 유량계 등의 센서를 설치하여 관로 흐름을 상시 감시하며, 노후되거나 슬러지가 축적된 관로는 문제가 발생하기 전에 교체 공사를 지시 할 수 있어야 한다. 본 논문에서는 하수(오수, 우수)도 맨홀 내 정보를 감지하여 실시간으로 전달, 판단, 처리 및 제어 할 수 있는 M2M/IOT 기반의 하수(오수, 우수)도 맨홀 내 모니터링 시스템을 설계 구현한다.

• Tunnel and Underground Space
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• v.21 no.5
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• pp.333-340
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• 2011

RMR is most strongly adopted rock classification method to scheme support system in domestic tunnel. However the RMR, which is based on geological survey during design stage of tunnel, can't present the real ground accurately. In this study, authors suggested Weighted-RMR (W-RMR) which is considered weighted value of risk factors of collapse due to prevent collapse and roof falls during tunneling. According to the application of W-RMR to Bye-Gye tunnel, we could change support type flexibly by the risk factors on a face of tunnel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.13-24
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• 2014

This paper presents development of artificial neural network(ANN) based prediction method for section forces of TBM tunnel segment lining in an effort to develop an automatized design technique. A series of design cases were first developed and subsequently analyzed using the two-ring beam finite element model. The results were then used to form a database for use as training and validation data sets for ANN development. Using the database, optimized ANNs were developed that can readily be used to predict maximum sectional forces and their distributions. It is shown that the compute maximum section forces and their distributions by the developed ANNs are almost identical to the computed by the two-ring beam finite element model, implying that the developed ANNs can be used as design tools which expedite routine design calculation process. The results of this study indicate that the neural network model can be effectively used as a reliable and simple predictive tool for the prediction of segment sectional forces for design.

• The Journal of the Petrological Society of Korea
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• v.16 no.4
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• pp.196-207
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• 2007

Miocene basalt plugs in Goseong contain a large variety of crustal and mantle xenoliths and xenocrysts. One of basalt plugs, Unbongsan, are derived from 160 km depth. Whole-rock geochemistry and pressure and temperature conditions of mineral phases indicate that Unbongsan volcanic rocks are alkali basalts and the source magma of the alkali basalts was generated from about $0.2{\sim}2%$ partial melting of depleted garnet peridotite. Crystallization pressures and temperatures of mineral phases within ascending magma of Unbongsan alkali basalt indicate that olivines, clinopyroxenes, and plagioclases were crystallized at $75{\sim}110km,\;40{\sim}52km,\;37{\sim}54km$ depth, respectively. The ascending magma of Unbongsan alkali basalts enclosed mantle xenoliths at about $57{\sim}67km$ depth.

• Journal of the Korean GEO-environmental Society
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• v.15 no.4
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• pp.53-60
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• 2014

There have been vast amounts of the site investigation data from the domestic construction sites every year and various national research institutes are constructing the database for the site investigation data. According to the Ministry of Land, Transport and Maritime Affairs, the database for the site investigation has been constructed for covering 154,000 individual boreholes since the computerization project for the geotechnical information started at 2000. It is considered to be high time to evaluate the reliability of the stored DB so that the current DB should be utilized to the various fields related to the planning and site investigation of the construction activities. Therefore, the precision of the stored site investigation data was evaluated via normal distribution for more active sharing and utilization. As a preliminary evaluation of the precision, the locations of the encountered strata from two different sites were analyzed. After the precision of the stored data is determined, the level of reliability of the each category of the stored geotechnical information would be determined and the users would be able to decide which information could be utilized.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.1
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• pp.29-36
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• 2007

Despite the role of tunnels in today's roadway environment, the study on tunnel lighting is still scant. Drivers passing through a tunnel face some difficulties caused by the visual differences between outside and inside of the tunnel. The whitehole phenomenon at a tunnel exit-zone severely decreases the driver's visibility in the daytime. A probeam lighting is generally recommended for the prevention of it. This paper simulates an exit-zone with a whitehole phenomenon to verify the effect of probeam lighting. Even though the tunnel lighting is important, it is not easy to consider enough number of lighting alternatives at the stage of tunnel design due to the complexity of tunnel conditions. This paper is expected to contribute improving the visibility in tunnels, especially at the exit-zone.