• 제목/요약/키워드: hard rock boring

검색결과 21건 처리시간 0.035초

지하철공사에서 풍화대용 쉴드 TBM의 경암 구간 굴진 시 대체공법에 대한 사례연구 (A Case Study on Penetrating Hard Rock with Alternative Methods of Shield TBM for Weathered Layer in Subway Construction)

  • 박형근;고원근
    • 대한토목학회논문집
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    • 제30권6D호
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    • pp.623-629
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    • 2010
  • 최근 도심지 굴착 시 고효율 급속시공이 가능한 쉴드 TBM(Tunnel Boring Machine) 공법의 도입이 점진적으로 증가하고 있다. 그러나 해당 장비에 대한 이해부족과 현지 지반조건을 충분히 고려하지 않은 상태로 쉴드 TBM의 설계 및 선정시 시공능력의 저하, 시공기간의 연장 및 공사비의 증가를 초래하는 경우가 빈번히 발생되고 있다. 이에 따라 본 사례연구에서는 풍화토, 풍화암 굴착에 적합하도록 설계된 쉴드 TBM 터널 굴착현장을 대상으로 쉴드 TBM 굴진 시 사전 지반조사의 결과와 달리 예기치 못한 경암구간 돌출로 굴진 중단 및 공기지연을 최소화하고자 적용된 대체공법의 적용성을 비교 분석하였다. 또, 터널 상 하행선 경암굴착에 적용된 대체공법의 선정부터 적용 후 결과에서 얻어진 굴진자료와 쉴드장비의 굴진속도, 공사기간, 공사비 등을 검토하여 연구대상 현장에 가장 적합한 대체공법을 판단 및 평가하였다. 본 연구의 결과를 요약하면 다음과 같다. 첫째, 굴진중단 및 대체공법 적용으로 인한 공사비, 공사기간의 증가를 방지하려면 대상현장의 정확한 지반조사가 선행되어야 하며, 이를 바탕으로 현장 지반조건에 가장 적합한 쉴드장비를 선정하는 것이 중요하다. 둘째, 대상현장에서 시행한 대체공법의 적용성을 분석한 결과, 경암구간 굴착을 위한 대체공법의 최선안은 개착 공법 후 경암 발파제거 공법임을 알 수 있었다.

암반터널에서의 TBM 공법 적용 사례 분석을 통한 운영 개선 방안 (A Study on the Operation Development Method through the Application Result TBM Tunneling in the Bard Rock)

  • 송용선;최재진;박홍태
    • 한국산학기술학회논문지
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    • 제9권4호
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    • pp.1050-1058
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    • 2008
  • 현재, TBM 공법의 적용은 1985년 이래로 점진적으로 증가되고 있는 추세에 있다. 본 연구는 암반터널에서 탁월한 굴진실적을 갖고 있는 TBM 공법의 이해와 운영상의 발전을 위해서 TBM 공법을 적용한 시공 사례의 시간손실과 TBM 굴진장의 상관관계를 분석하였다. 그리고 분석결과를 기 분석된 미국, 일본의 운영현장의 결과값과 비교하여 TBM 굴진에 영향을 주는 요인을 분석하였고 그 분석결과에 따른 운영 개선 방안을 제시하였다. 따라서 본 연구에서 제시한 개선 방안은 향후 기본계획수립단계에서 TBM 공법 적용시 개략적인 지표로 활용할 수 있는 중요한 자료가 될 것으로 사료된다.

포항지역 신생대 제3기 미고결 퇴적층의 암반분류 (Rock Mass Classification of Tertiary Unconsolidated Sedimentary Rocks In Pohang Area)

  • 김성욱;최은경;이융희
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 춘계 학술발표회
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    • pp.999-1008
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    • 2009
  • A series of sedimentary rocks which are formed in the Tertiary are distributed around Samcheok(Samcheok-Pukpyoung basin), Younghae(Younghae basin), Pohang(Pohang basin), Gyeongju(Yangnam basin), Ulsan(Ulsan basin), Jeju(Seogyuipo formation) in the southern region of the Korean Peninsula. This study concerned with geological, geophysical, geotechnical properties of the unconsolidated rocks in the Pohang area. A consolidated rocks are classified as hard rock - soft rock - weathered rock - residual soil follows in degree of weathering. But unconsolidated rocks has soil properties as well as rock's at the same time. The results of field excursion, boring, borehole-logging, rock testing, geophysical survey, laboratory test are soft rock range, but the durability of the rock until the residual soil from the weathered rock. We accomplished the rock mass classification of the unconsolidated rocks.

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Design and optimization of layout patterns for rock TBM cutterheads

  • Ebrahim Farrokh
    • Geomechanics and Engineering
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    • 제38권2호
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    • pp.179-189
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    • 2024
  • This paper presents a geomechanical framework for designing and optimizing layout patterns of cutterheads for rock Tunnel Boring Machines (TBMs), aiming to enhance their engineering performance. By examining the forces and moments exerted by rock, the study addresses geometric constraints associated with cutter boxes in key regions of the cutterhead, including the center, face, and gage areas, as well as the three-dimensional effects of cutterhead curvature on the geometric constraints of the back of the cutter boxes in the gage area. Novel formulas are proposed for determining the center points of cutter boxes and calculating both the minimum angular spacing and distance spacing between consecutive cutter boxes along a spiral path. The paper outlines an optimized layout design process for four cutterhead configurations: random, random paired, radial, and double spiral designs. Examples are provided to illustrate the results of applying these designs. The findings underscore the efficacy of the proposed methods in achieving a uniform and symmetrical distribution of cutters and buckets on the cutterhead surface. This approach effectively eliminates boundary overlap and minimizes unbalanced forces and moments. From a geomechanical standpoint, this framework offers a robust strategy for enhancing the performance and reliability of TBM cutterheads in rock tunneling operations.

대구경 터널공법 적용 사례분석을 통한 운영 개선방안 (A Study on the Operation Development Method through the Application Results Large-Diameter Tunnel)

  • 이양규
    • 한국재난정보학회 논문집
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    • 제8권2호
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    • pp.108-118
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    • 2012
  • 현재 TBM공법의 적용은 1985년 이래로 점진적으로 증가되고 있는 추세에 있다. 이 연구는 암반터널에서 탁월한 굴진실적을 갖고 있는 TBM공법의 이해와 운영발전을 위해서 TBM공법을 적용한 시공 사례의 시간손실과 TBM 굴진장의 상관관계를 분석하였다. 그리고 분석 결과를 기 분석된 국내, 미국, 일본의 현장 결과치와 비교 분석하여 TBM 굴진에 영향을 주는 요인을 분석하였고, 그 분석결과에 따른 운영개선방안을 제시하였다. 따라서 이 연구에서 제시한 개선방안은 향후 기본계획수립단계에서 TBM공법 적용 시 개략적인 지표로 활용할 수 있을 것으로 사료된다.

경암반에서 TBM 굴진 해석 및 평가 (Analysis and Assessment of Tunnel Boring Machine Performance in Hard Rock)

  • 배규진;이용수;홍성완;박홍조
    • 터널과지하공간
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    • 제4권2호
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    • pp.144-155
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    • 1994
  • This research is designed to assess current achievement levels for mechanized excavation systems in Korea adn suggest the model predictive of TBM performance using statistical approaches. A test section in the TBM construction sites is selected to measure and analyze TBM performance. The field records including operating data, time allocation into downtime catagories, and machine design are analyzed on a shift basis. There are a total of 240 shifts, with most days operating two shifts per day. Examples of the probability density functions produced from the test section are presented and discussed. Relationships between TBM penetration rate and rock physical properties are investigated and the empirical equations for TBM performance prediction are also assessed with the field data.

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Estimation of the excavation damage zone in TBM tunnel using large deformation FE analysis

  • Kim, Dohyun;Jeong, Sangseom
    • Geomechanics and Engineering
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    • 제24권4호
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    • pp.323-335
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    • 2021
  • This paper aims to estimate the range of the excavation damaged zone (EDZ) formation caused by the tunnel boring machine (TBM) advancement through dynamic three-dimensional large deformation finite element analysis. Large deformation analysis based on Coupled Eulerian-Lagrangian (CEL) analysis is used to accurately simulate the behavior during TBM excavation. The analysis model is verified based on numerous test results reported in the literature. The range of the formed EDZ will be suggested as a boundary under various conditions - different tunnel diameter, tunnel depth, and rock type. Moreover, evaluation of the integrity of the tunnel structure during excavation has been carried out. Based on the numerical results, the apparent boundary of the EDZ is shown to within the range of 0.7D (D: tunnel diameter) around the excavation surface. Through series of numerical computation, it is clear that for the rock of with higher rock mass rating (RMR) grade (close to 1st grade), the EDZ around the tunnel tends to increase. The size of the EDZ is found to be direct proportional to the tunnel diameter, whereas the depth of the tunnel is inversely proportional to the magnitude of the EDZ. However, the relationship between the formation of the EDZ and the stability of the tunnel was not found to be consistent. In case where the TBM excavation is carried out in hard rock or rock under high confinement (excavation under greater depth), large range of the EDZ may be formed, but less strain occurs along the excavation surface during excavation and is found to be more stable.

파주 지방산업단지 대절토사면 설계 및 시공사례 (A Case Study on Design and Consruction for Cut Slope in Pa-ju Local Industrial Complex)

  • 이종구;권민석;백영식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 지반공학 공동 학술발표회
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    • pp.210-220
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    • 2005
  • We have analyzed the stability for cut-slopes at main street 3-2 line section in Pa-ju local industrial complex. After studying an additional boring test, laboratory test and face mapping etc., we have determined the extent of reinforcement, slope inclinations and soil strength parameter from the analysis of test results. After changing the inclination of slopes for ground limit and carrying out the analysis of slope stability, we applied the Mass Nailing Method to the site because of need for reinforcement to soil and weathered rock slopes. In slope for soft and hard rock sections, we also reinforced the sections that are difficult to obtain the safety without reinforcement in alteration zone.

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Estimation of the zone of excavation disturbance around tunnels, using resistivity and acoustic tomography

  • Suzuki Koichi;Nakata Eiji;Minami Masayuki;Hibino Etsuhisa;Tani Tomonori;Sakakibara Jyunichi;Yamada Naouki
    • 지구물리와물리탐사
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    • 제7권1호
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    • pp.62-69
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    • 2004
  • The objective of this study is to estimate the distribution of a zone disturbed by excavation (EDZ) around tunnels that have been excavated at about 500 m depth in pre-Tertiary hard sedimentary rock. One of the most important tasks is to evaluate changes in the dynamic stability and permeability of the rock around the tunnels, by investigating the properties of the rock after the excavation. We performed resistivity and acoustic tomography using two boreholes, 5 m in length, drilled horizontally from the wall of a tunnel in pre-Tertiary hard conglomerate. By these methods, we detected a low-resistivity and low-velocity zone 1 m in thickness around the wall of the tunnel. The resulting profiles were verified by permeability and evaporation tests performed at the same boreholes. This anomalous zone matched a high-permeability zone caused by open fractures. Next, we performed resistivity monitoring along annular survey lines in a tunnel excavated in pre-Tertiary hard shale by a tunnel-boring machine (TBM). We detected anomalous zones in 2D resistivity profiles surrounding the tunnel. A low-resistivity zone 1 m in thickness was detected around the tunnel when one year had passed after the excavation. However, two years later, the resistivity around the tunnel had increased in a portion, about 30 cm in thickness, of this zone. To investigate this change, we studied the relationship between groundwater flow from the surroundings and evaporation from the wall around the tunnel. These features were verified by the relationship between the resistivity and porosity of rocks obtained by laboratory tests on core samples. Furthermore, the profiles matched well with highly permeable zones detected by permeability and evaporation tests at a horizontal borehole drilled near the survey line. We conclude that the anomalous zones in these profiles indicate the EDZ around the tunnel.