• 한국구조물진단유지관리공학회 논문집
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• 제7권3호
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• pp.215-222
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• 2003

최근 도심지 지하공간 활용을 위한 굴착공사가 기존의 건물주변에서 대형화, 대심도화 되고 있다. 굴착공사에서 발생되는 토압은 지반조건, 굴착깊이, 시공방법, 벽체 지지구조 등과 같은 여러 가지 요인에 의해 영향을 받으므로 정확히 산정하기가 매우 어렵다. 본 연구에서는 지하철건설현장에 설치된 하중계, 변형율계, 지중경사계와 같은 현장계측기로부터 측정된 계측자료를 선정하여 지반굴착시 흙막이벽체의 최대수평변위와 분포형태 그리고 실측된 Strut 축력으로부터 환산토압을 산정하여 단계별 굴착깊이에 따른 축력거동 양상과 토압분포 형태를 비교 검토하였다. 연구결과 점성토 지반에서의 실측토압은 Tschebotarioff의 경험토압과 Terzaghi-Peck의 경험토압의 합성 형태를 보이고 있다.

• 화약ㆍ발파
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• 제39권2호
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• pp.15-26
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• 2021

2013년부터 국산 전자뇌관이 출시되면서 많은 석산 및 건설현장에서 폭넓게 사용되어지고 있다. 도심지에서 이루어지는 SOC 프로젝트의 경우, 대부분 민원을 줄이기 위해 대심도로 설계가 이루어지는 추세이다. 대심도 굴착개발은 작업구 및 환기구 등의 시공에 많은 시간과 비용이 발생된다. 현장 인근에 보안물건이 위치한 경우, 기계식굴착공법을 적용하는 경우가 있으며, 이러한 기계식굴착방법은 암반의 강도 및 굴착장비의 성능에 따라 영향을 받는다. 기계식 굴착공법의 작업효율이 떨어지는 경우, 공사기간이 늘어나면서 비용이 증가하는 문제가 발생하고 있다. 본 사례는 도심지내 대심도 수직구 현장에서 기계식굴착공법으로 설계된 현장을 전자뇌관 발파공법으로 전환한 사례이다. 전자뇌관을 이용하여 발파소음과 진동에 대한 환경규제기준을 충족시키면서 공사기간을 단축시켰다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1008-1013
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• 2006

Ground anchor method is widely used in the large scale deep excavation of urban area to support a retained wall. Excavation using the ground anchor as a supporting system near a building have many difficulties due to the limitation of construction space. This method can not be applied to the site with the insufficient space from the retained wall to the boundary line. In this case, soil improvement at the anchor bond zone can be used to secure the frictional resistance of ground anchor within the boundary. Through this method, the bond length of anchor can be shortened considerably. This paper deals with the case study on the ground excavation adjacent to a building. The object field is Yongsan Park Tower Construction Site. In this site, the enlarged anchor with soil improvement was applied to solve the problem due to the limitation of construction space. According to the results of field test and monitoring, the anchor with soil improvement is very effective to secure the frictional resistance at the anchor bond zone.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.268-275
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• 2006

Excavation works of cylindrical shafts and tunnels for the construction of a variety of infrastructures have been frequently going on in the urban areas. When ground excavations of cylindrical shafts and shallow tunnels proceed in the ground condition of high water level and silt particle component, ground water drawdown involving soil particle migration causes loosening of ground around tunnels and shafts, causes settlement and deformation of ground. Damages due to ground sinking and differential settlement can occur in the adjacent ground and structures. The extent and possibility of damage relevant to ground water drawdown and soil particle migration can't be so precisely expected in advance that we will face terrible damages in case of minor carefulness. This paper introduces two examples of construction management where using incremental deformation graph of inclinometer, we noticed the possibility of soil migration due to ground water drawdown in the excavation process of vertical shaft and shallow tunnel, analysed a series of measurement data in coupled connection, properly prepared countermeasures, so came into safe and successful completion of excavation work without terrible damages. The effort of this article aims to improve and develop the technique of design and construction in the coming projects having similar ground condition and supporting method.

• KEPCO Journal on Electric Power and Energy
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• 제7권2호
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• pp.285-293
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• 2021

The construction of underground structures such as power supply lines, communication lines, utility tunnels has significantly increased worldwide for improving urban aesthetics ensuring citizen safety, and efficient use of underground space. Those underground structures are usually constructed along with vertical cylindrical shafts to facilitate their construction and maintenance. When constructing a vertical shaft through the open-cut method, the walls are mostly designed to be flexible, allowing a certain level of displacement. The earth pressure applied to the flexible walls acts as an external force and its accurate estimation is essential for reasonable and economical structure design. The earth pressure applied to the flexible wall is closely interrelated to the displacement of the surrounding ground. This study simulated stepwise excavation for constructing a cylindrical vertical shaft through a centrifugal model experiment. One quadrant of the axisymmetric vertical shaft and the ground were modeled, and ground excavation was simulated by shrinking the vertical shaft. The deformation occurring on the entire ground during the excavation was continuously evaluated through digital image analysis. The digital image analysis evaluated complex ground deformation which varied with wall displacement, distance from the wall, and ground depth. When the ground deformation data accumulate through the method used in this study, they can be used for developing shaft wall models in future for analyzing the earth pressure acting on them.

• 한국터널지하공간학회 논문집
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• 제26권2호
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• pp.153-167
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• 2024

최근 도심지에 개발이 이루어지면서 지반침하가 증가하고 있으며, 그에 대한 원인 중 하나는 지하수위의 변화이다. 본 연구에서는 굴착깊이가 깊은 수직구 굴착공사의 한 예로 ｢◯◯◯◯ 복선전철 민간투자사업｣의 작업구를 대상으로 지하수위 저하량에 대한 현장계측 결과와 수치해석 결과를 비교 분석하였다. 이를 통하여 지하수위 저하에 대한 검토를 실시할 경우, 현장조건들이 충분히 반영될 수 있도록 지반조건을 분석하여 적용하여야 하며, 지하수위는 측정시기를 확인하여 적절한 수위를 적용하여야 시공 시 지하수위의 저하량과 유사한 예측 값을 도출해 낼 수 있음을 확인하였다.

• 건축역사연구
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• 제31권2호
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• pp.51-65
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• 2022

Seoju is one of the nine weeks of the ancient period, and according to literature records, the construction of Seojuseong Fortress has a long history of 2573. This is the land of Oseongtong-gu, a political and military hub, and flood disasters have frequently led to frequent reconstruction of fortresses. In particular, it is also an important place to show that the function of the fortress is defensive and has a function of preventing floods. This study analyzed the shape of Seojuseong Fortress and the characteristics of urban spaces in the Myeongcheong period through excavation data and literature data.

• 지질공학
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• 제29권2호
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• pp.137-151
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• 2019

굴착공사 중 발생할 수 있는 지반함몰 사고를 방지하기 위해 굴착공사 주변 지층변화를 분석하고 모니터링하는 탐사기법과 기술이 필요함에 따라 다양한 탐사기술들을 적용, 보완함으로써 해석 기법을 향상시키는 것이 요구된다. 이 연구에서는 굴착공사 중 발생할 수 있는 지반침하 위험요소와 굴착, 지하수 등에 의한 이완영역을 탐지하기 위한 실규모 현장 실험을 실시하였다. 현장 실험을 수행하기 위해 실규모 굴착현장 테스트베드를 구축하고, 도심지 현장을 고려한 탐사법 중 전기비저항 탐사, 다중채널분석표면파탐사를 활용, 각 개별탐사의 적용 유효성 검토 및 모델링을 이용한 최적 탐사변수 도출과 설계, 탐사결과의 상호연관성을 비교 해석하였다. 이 연구 결과, 각 탐사별로 이완영역에 대한 영향을 확인할 수 있었으며, 특히 전기비저항탐사를 이용해 지하수면 위치를 확인하고 굴착에 대한 영향 파악할 수 있었다. 추후 지하수의 영향을 고려한, 즉 굴착면을 고려한 모델링에 대해 추가 연구가 필요할 것으로 보인다.

• Geomechanics and Engineering
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• 제36권5호
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• pp.417-426
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• 2024

Shield tunneling method is widely used to build tunnels in complex geological environment. Stability control of tunnel face is the key to the safety of projects. To improve the excavation efficiency or perform equipment maintenance, the excavation chamber sometimes is not fully filled with support medium, which can reduce the load and increase tunneling speed while easily lead to ground collapse. Due to the high risk of the face failure under non-fully support mode, the tunnel face stability should be carefully evaluated. Whether compressive air is required for compensation and how much air pressure should be provided need to be determined accurately. Based on the upper bound theorem of limit analysis, a non-fully support rotational failure model is developed in this study. The failure mechanism of the model is verified by numerical simulation. It shows that increasing the density of supporting medium could significantly improve the stability of tunnel face while the increase of tunnel diameter would be unfavorable for the face stability. The critical support ratio is used to evaluate the face failure under the nonfully support mode, which could be an important index to determine whether the specific unsupported height could be allowed during shield tunneling. To avoid of face failure under the non-fully support mode, several charts are provided for the assessment of compressed air pressure, which could help engineers to determine the required air pressure for face stability.

• 산업기술연구
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• 제22권A호
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• pp.107-117
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• 2002

The blast works for open cuts and underground constructions near urban areas have recently increased complaint of ground vibration, air blast and fly rock. In order to reduce these problems, it is necessary to develop more cautious blasting, or non-blast excavation methods by mechanical power. For these breaker workings instead of blast are sometimes adopted. To compare the characteristics of blast vibration with breaker vibration, the level, range of frequency and spectrum amplifications of each vibration were studied.