• Journal of Korean Tunnelling and Underground Space Association
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• 제17권6호
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• pp.605-614
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• 2015

A room-and-pillar underground structure is characterized by its grid-type array of room and pillar. As a result, its construction and economical efficiency can be governed by excavation sequence. In this study, the construction period by the drill and blast method which can be treated as a main sequence for excavation was examined by considering the regulation for blasting and construction standard of estimation in Korea. To evaluate the construction period for the room-and-pillar underground structure constructed in 4 kinds of square-type area ($30{\times}30{\sim}57{\times}57m$), the concurrent excavation pattern which was suggested in the previous researches was used. From the suggested condition, the total construction period by drill-and-blast method can be estimated with the consideration of the construction area, number of jumbo drill and faces in operation.

• Journal of the Korean GEO-environmental Society
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• 제7권4호
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• pp.63-71
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• 2006

This study was conducted to evaluate air injection mode on stabilization of landfill gas and to predict the time for landfill mining. It took 8 times longer for pulse aeration to get to aerobic condition, compared to continuous aeration. It was evaluated that continuous aeration mode is more preferable than pulse mode for rapid air exchange in landfill mining. High correlation ($r^2$ = 0.95) was found between continuous aeration time and time to maintain aerobic condition when $0.2m^3/min$ of air was continuously injected and stopped. The aerobic condition ($CH_4$ < 5%) was maintained for 1.5 times longer than aeration time.

• Magazine of korean Tunnelling and Underground Space Association
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• 제5권4호
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• pp.6-17
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• 2003

라이닝과 굴착작업은 통상적으로 병행작업이 되며, 라이닝은 시공속도가 빠르기 때문에 공기는 주로 굴착 속도에 지배된다. 그러나 소단면/원형단면 터널에서는 작업 공간확보문제 등 제반조건에 따라 굴착과 라이닝 작업이 분리되어 라이닝 공정이 전체 공기에 커다란 영향을 끼치는 경우도 있다. 라이닝 콘크리트의 타설시기는 계측에 의해 원지반의 변위가 수렴된 것을 확인한 후 하는 것이 원칙이다. 따라서 NATM 에서는 전단면 라이닝이 일반적이다. 본 고에서는 라이닝 설비로서 사용되는 타설설비, 운반설비, 형틀설비의 총 3편으로 나누어 라이닝 기계에 대하여 설명하도록 한다.

• Journal of the Korean Geotechnical Society
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• 제25권4호
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• pp.55-68
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• 2009

A new borehole roughness and verticality measurement system (BKS-LRPS) for rock socketed drilled shafts were developed and verified its field application. The stability of BKS-LRPS was verified for several field conditions, which included the effect of measuring unit shaking, the application of water/air calibration factors, and the resistance of high water pressure inside piles. Also, effective measurement distances for various conditions of turbidity were defined in the field by measuring borehole roughness and vertical alignment for 6 drilled shafts. Vertical alignments for all drilled shafts could be measured by BKS-LRPS. However, borehole roughness was not able to be measured due to high turbidity caused by RCD drilling processing. Based on the BKS-LRPS field verification, BKS-LRPS is the first borehole roughness and verticality measurement system applying both in the water and air.

• KSCE Journal of Civil and Environmental Engineering Research
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• 제32권5D호
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• pp.499-505
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• 2012

As the excavation depths during excavation works in urban sites are getting deeper and bigger, It is necessary to study for the improvements to solve the problems in the excavation processes. This research deals with the excavation method that can not only minimize the effect on the surrounding constructions, but also shorten the construction period of the excavation work. For this research, there have been an extensive literature review of the bibliographic data about Slurry Wall Method, which is recognized around the world, and the analysis of the major problems in the existing ineffective construction step. These efforts led to the technical improvements. Accordingly, a new construction method applied with the new technical factors has been suggested, and it was possible to compare Slurry Wall Method with the construction method and analyze them on the base of the examples using the suggested method. This new method decreased the excavation period by 15 days. It took only 33days to finish the excavation work, as compared to 48 days that can be seen on the pre-modification schedule. Furthermore, the suggested method in this research is safer, more economically feasible, and better for the environment than Slurry Wall Method. It will contribute to shortening the construction period of Slurry Wall Method in the end.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.282-286
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• 2009

1979년 준공된 수도권 광역상수도 1단계 시설은 상당한 노후화가 진행되었을 것으로 예상되며, 또한 향후 한강하류권 용수공급계획이 예정되어 있어 내부부식 및 관로손상부 개량의 시급성이 제기되었다. 이에 따라 직경 2,800${\sim}$800mm의 초대구경 도수관 53.9km의 개량을 위한 사업이 추진되었으며 시공성, 환경성, 경제성 등의 여러 항목에 대한 검토 결과 신개념 녹색공법인 비굴착식 건식일체형 공법이 최종 선정되었다. 그동안 기존관 개량공사에서 주로 사용되었던 굴착공법이 굴착에 따른 공기지연, 소음 분진 악취 등의 환경오염, 전구간 굴착에 따른 공사비 증가 등 많은 문제점을 안고 있는 것에 반해, 동사업에서 채택된 비굴착공법은 관로내에서 작업이 이루어지므로 공기단축, 환경오염 최소화에 따른 민원발생 최소화, 작업구만 굴착함에서 오는 공사비 절감 등 상대적으로 훨씬 우수한 것으로 평가된다. 동공법에 따르면 관내부 갱생공사는 '배수 및 잔류토사 제거'${\to}$'관내건조'${\to}$'표면처리'${\to}$'프라이머도장'${\to}$'본도장'의 순으로 진행된다. 일체형 장비에 의한 이와 같은 초대형관의 자동화시공은 세계에서 처음 적용되는 것이다.

• Proceedings of the Korea Contents Association Conference
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• 한국콘텐츠학회 2016년도 춘계 종합학술대회 논문집
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• pp.71-72
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• 2016

본 논문은 건식 내부 굴착 매립 간척공법(Dry Internal Project Land Digging Reclamation Method, DIPLDRM)[3] 호소의 대기 환경 개선을 위한 미세먼지 조절 IOT 모듈을 개발하는데 목적으로 하고 있다. 이를 위해 공기오염 중 인체에 가장 영향을 많이 미치는 미세먼지를 측정할 수 있는 공기오염 측정 시스템을 위한 공기 상태 변화를 Web 브라우저를 제안한다. 또한 본 연구는 외부 대기 상태와 디바이스로부터 측정된 내부 대기상태를 비교할 수 있도록 시각화함으로써 사용자의 편의성을 증대시킬 수 있을 것으로 판단된다.

• Korean Journal of Construction Engineering and Management
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• 제20권2호
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• pp.37-43
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• 2019

After the new standards for labor hours has been released, various problems come up in construction field, such as income reduction of employees, extension of construction period and increased construction cost. Although it is expected that the impact of the new standard on the construction industry is more worse than other industries form the view of productivity, not much works have been done to identify those impacts. Thus, this research proposes the standard construction processes, excavation cycle, and unit construction period for NATM tunnel project based on 'Construction Standard Production Rates.'The study also investigated the impact of reduced labor hours on the management of work crews, construction periods and costs of tunnel projects. The results showed that under the 52 labor hour standard, the construction periods for the excavation work and whole project was increased by 20% and 8.9%, respectively, but the construction costs for the excavation work and whole project was decreased by 1.4% and 0.6%, respectively.

• Journal of Korea Soil Environment Society
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• 제3권2호
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• pp.79-88
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• 1998

The purpose of this study was to estimate the removal potential of landfill gases during landfill mining project. Air injection mode and landfill gas extraction mode were tested. A mode that air injected at one injection well and landfill gas extracted at another extraction well at the same time was also tested to compare. The flow rates of all modes were the same as 15$\textrm{km}^2$/min. Air injection mode was the most effective in removing $CH_4$. Air injection/extraction mode didn't improve the effectiveness of removing CH$_4$compared with air injection mode. Air injection mode were more advantageous than air injection/extraction mode in respect to energy consumption because that of air injection/extraction mode were doubled.

• Journal of the Korea Organic Resources Recycling Association
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• 제12권3호
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• pp.76-85
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• 2004

Anaerobic decomposition of municipal solid waste (MSW) had potential adverse impacts such as the production of methane and long-term post closure on human health and the environment. It was demonstrated that aerobic degradation of MSW resulted in the reduction of a methane yield and the enhancement of stabilization of MSW. Excavated solid wastes were both aerobically and anaerobically treated in order to evaluate the effects of air injection on the stabilization of landfill site. The municipal solid waste (MSW) samples were excavated from a 10-year old landfill (operation period: 1991. 11~1994. 11), Jeonju, Korea. Excavated municipal solid wastes are primarily composed of soils and vinyl/plastics. For the two aerobic simulated lysimeters, the levels of $O_2$ ranged 1.6~23.1% and the levels of $CO_2$ ranged 1.5~15.1%, which confirmed the aerobic decomposition. Aeration did prevent methane formation. For the anaerobic simulated lysimeter, the $CO_2$ rose as $O_2$ was consumed and low levels of CH4 were produced. The pH levels ranged from 7.7 to 8.9 for anaerobic lysimeter and from 7.3 to 8.5 for aerobic lysimeters. As expected, aerobic treatment proved to enhance the removal of biodegradable materials in the excavated solid wastes when monitoring the concentration of BOD, COD, $NH_4-N$, and $NO_3-N$ in the leachate.