• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.669-676
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• 2023

This study analyzed the relationship between major parameters and numerical analysis results according to various excavations conducted around the urban railway, application of machine learning techniques and verified the scope of influence of the adjacent excavation on the existing urban railway box structure and the appropriateness of the safety area. This study targeted the actual negotiated adjacent excavation works and box structures around the urban railway, and the analysis was conducted on the most representative two-line box structures. The analysis confirmed that the difference in depth of urban railway, excavation depth of adjacent excavation, and depth of underground water level are important parameters, and the difference in excavation depth of adjacent excavation is the parameter that affects the behavior of underground box structures and is an important requirement for setting safety areas. In particular, the deeper the depth of the adjacent excavation work, the greater the effect on the deflection of the underground box structure, and the horizontal separation distance, one of the important requirements for determining the management grade of the existing adjacent excavation work, is relatively small.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2001.03a
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• pp.132-138
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• 2001

홍콩 HMRT(Hongkong Mass Railway Tunnel) 지하철 공사현장에서는 터널굴착시 나타난 고경사절리로 인해 상당한 여굴이 발생하였다. 이에 대한 원인을 규명하기 위하여 각 터널별로 발생한 여굴의 양과 위치 등을 조사하고 이를 입찰설계단계에서 이루어진 시추공조사와 굴착단계에서의 막장검측에 의한 지질조건과 서로 비교, 분석하였다. 터널굴착에서 발생하는 여굴은 막장의 고경사 절리의 분포와 방향에 의해 영향을 받았으며, 암반조건 RQD, Q'와도 밀접한 관계를 가지는 것으로 나타났다. 본 현장의 분석에 따르면 터널설계시 고경사절리의 존재여부 및 분포, 방향성 등을 면밀히 조사하고 해석하여 사전에 여굴의 발생 가능성을 확인하는 것이 필요하다.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.107-115
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• 2001

해성토층 위에 준설매립된 수도권 해안매립지역에서 원형의 대심도 굴착공사로 인하여 발생하는 지중연속벽의 수평변위를 예측하기 위하여 수치해석을 수행하였고, 이러한 수치해석결과와 현장측정값을 비교하여 각각의 수치해석방법의 적용성을 평가하였다. 수치해석법으로는 지반반력해석, 선형 유한요소법 그리고 비선형 유한요소법이 수행되었다. 각각의 방법들에서는 미소변형률에서의 지반거동특성인 비선형성과 굴착으로 인한 구속압감소효과를 고려한 경우와 고려하지 않은 경우에 대하여 수치해석을 수행하여 각각 그 결과들을 비교.분석하였다. 이러한 분석결과 미소변형률에서의 비선형성과 굴착으로 인한 구속압감소 효과를 고려한 비선형 유한요소해석법이 가장 정확하게 수평변위를 예측할 수 있는 방법임을 알 수 있었다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.183-195
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• 2018

Recently, the need for research on vertical shaft excavation is increasing with the increase of the demands for the underground and utility tunnels. As a part of the R&D project of the Ministry of Land, Infrastructure and Transport, CUT (center for utility tunnel) has developed "Ring cut method". "Ring cut method" is a method to improve the stability of the ground against the basal heave by excavator wall pre-penetration during vertical shaft excavation. In this study, the basal heave was simulated by centrifugal model test. The basal heave, ground subsidence, and ground deformation of surrounding ground were analyzed by soil plug effect from wall pre-penetration. It was found that the soil plug could control the basal heaving and ground subsidence, and verified that the 'Ring cut method' could be a good countermeasure for the ground stability against the basal heave.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.163-171
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• 2006

The behaviors and design procedures of building excavation plane in innovative prestressed support (IPS) system are presented in this paper. Determination procedure for initial pretension in IPS wale subjected to design earth pressure is derived. The computer analysis model under uniform and non-uniform earth pressure is constructed using beam element for the IPS wale, tension-only element for cable, and compression-only element for soil. Axial forces and bending moments of IPS wale under initial pretension and design earth pressure are calculated. The combined stresses due to these axial force and bending moment are calculated and safety condition of building excavation plane is investigated.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1995.03a
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• pp.109-120
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• 1995

절리가 발달된 경암질 암반내에서 터널을 굴착할 때에 발생하는 심각한 문제중의 하나는 암반내에 존재하는 불연속면과 굴착에 의하여 형성되는 자유면에 의하여 생성된 블록의 낙반 사고이다. R.E. Goodman, Gen-hua shi$^{3)}$ 등에 의하여 제안된 블록이론은 암반사면이나 지하공동에 존재하는 절리들의 방향성을 조사하여 우세한 방향의 절리들에 의하여 발생하는 블록들의 안정, 불안정 및 낙반의 가능성 여부를 판정할 수 있도록 하였다. (중략)

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.6
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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 Society for Railway
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• v.12 no.2
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• pp.321-328
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• 2009

A optimal reinforcement in the joint rock slope excavation adjacent to an existing tunnel would be influenced by excavation distance from the tunnel, slope angel, and joint conditions but has been empirically determined so far. In this study, large scale model tests were conducted to find out the relationship between load translation on the excavation surface and bebavior of the tunnel according to excavation steps of the jointed rock slope. Consequently, two main parameters, joint dip and sloped angle were investigated in those model tests. From the test results, it was found that tunnel deformation was the largest one when the excavation of joints located closer to the tunnel crown or invert. Stability of the slope and the tunnel were varied in a certain excavation stage related to the angle of slope. In the future, based on results of this study the reinforcement method for the tunnel and slope safety in a jointed rock mass will be demonstrated.

• Geotechnical Engineering
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• v.1 no.2
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• pp.81-92
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• 1985

Braced excavation for a new building was carried out at a very close proximity of an existing tall building of T.hick columns are supported by indict.ideal spread footings on sand layer The excavation was planned to reach far below the footing level of the existing building. To assess the foundation performance and stability of the existing building, the behavior of 9round subjected to loss of confinement from excavation was analytically studied using finite element method. Field instrumentation was also conducted to monitor the actual ground responses during excavation. Based on these studies, various remedial measures weere taken to minimize the adverse effects to the building, and excavation was successfully completed. This paper presents the results from the analytical studies and field monitoring, and measured and measured responses at different stages of excavation.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.292-295
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• 2005

본 연구는 지하유류저장공동 굴착 시 비교적 정밀하게 해석된 단열체계 및 수리인자를 토대로 투수성구조영역과 수리암반영역으로 세분화하여 연구지역의 불규칙하고 복잡한 지하수유동체계를 해석해 보고자 하였다. FZ-2 구조대와 인접한 수리암반영역 Domain-A와 B는 Domain-C와 D에 비해 수평수벽공의 초기압이 최대 약 $15kg/cm^2$정도 높으며, 상 하부의 수리적 연결성이 양호하여 지하공동굴착 시 상 하부의 수위차가 크지 않고 지하수 함양량은 약 $35{\sim}50mm/year$의 범위를 보인다. 또한 공동굴착 시 투수성 단열과의 교차에 의한 수위강하에 민감한 반응을 보이며 상 하부의 수위강하양상이 유사한 특성을 나타낸다. 반면, FZ-1 구조대와 인접한 Domain-C와 D는 지하공동 부근의 수리전도도가 각각 $7{\times}10^{-10},\;2{\times}10^{-9}m/sec$로 Domain-A와 B에 비해 최대 약 6배정도 낮고, 상 하부의 수리적 연결성이 양호하지 않기 때문에 공동굴착 전 이중수위측정시설 설치 시 계측된 상 하부의 수위차는 최대 약 120 m로 매우 크다. 그리고 상부의 지하수는 하부의 낮은 수리전도도로 인하여 수직방향보다 수평방향으로의 유동이 우세하며 공동굴착 시 수위변화는 크지 않고 함양량은 $10{\sim}15mm/year$의 범위를 나타낸다.