• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1997년도 가을 학술발표회 논문집
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• pp.171-176
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• 1997

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1782-1788
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• 2007

This study analyzed ground settlement and ground stress depending on tunnel excavation and the ground reinforcing grouting methods for double line road tunnel through deep weathered zone. Diameter of double line road tunnel was approximately 12m and umbrella arch method and side wall reinforcing grouting were applied. The ring-cut split excavation method and CD-cut excavation method for excavation method were applied. Analysis of failure rate and vertical stress ratio show that the tunnel for which the height of the cover(H) was higher than four times the diameter, it can be considered a deep tunnel. Comparisons of various excavation and ground reinforcement methods were showed that CD-cut method results in lower surface and crown settlement, and lower failure rate than where using Ring-cut split method. In addition the side wall reinforcing grouting resulted in reduction of tunnel displacement and settlement.

• Geomechanics and Engineering
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• 제36권2호
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• pp.111-119
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• 2024

In the realm of rock excavation projects, precise estimation of the drilling rate index stands as a pivotal factor in strategic planning and cost assessment. This study introduces and evaluates two pioneering computational intelligence models designed for the prognostication of the drilling rate index, a pivotal parameter with direct implications for cost estimation in rock excavation projects. These models, denoted as the Relevance Vector Regression (RVR) optimized with the Invasive Weed Optimization algorithm (IWO) (RVR-IWO model) and the RVR integrated with the Shuffled Frog Leaping algorithm (SFL) (RVR-SFL model), represent a groundbreaking approach to forecasting drilling rate index. The RVR-IWO and RVR-SFL models were meticulously devised to harness the capabilities of computational intelligence and optimization techniques for drilling rate index estimation. This research pioneers the integration of IWO and SFL with RVR, constituting an unprecedented effort in forecasting drilling rate index. The primary objective of this study was to gauge the precision and dependability of these models in forecasting the drilling rate index, revealing significant distinctions between the two. In terms of predictive precision, the RVR-IWO model emerged as the superior choice when compared to the RVR-SFL model, underscoring the remarkable efficacy of the Invasive Weed Optimization algorithm. The RVR-IWO model delivered noteworthy results, boasting a Variance Account for (VAF) of 0.8406, a Mean Squared Error (MSE) of 0.0114, and a Squared Correlation Coefficient (R²) of 0.9315. On the contrary, the RVR-SFL model exhibited slightly lower precision, yielding an MSE of 0.0160, a VAF of 0.8205, and an R2 of 0.9120. These findings serve to highlight the potential of the RVR-IWO model as a formidable instrument for drilling rate index prediction, particularly within the framework of rock excavation projects. This research not only makes a significant contribution to the realm of drilling engineering but also underscores the broader adaptability of the RVR-IWO model in tackling an array of challenges within the domain of rock engineering. Ultimately, this study advances the comprehension of drilling rate index estimation and imparts valuable insights into the practical implementation of computational intelligence methodologies within the realm of engineering projects.

• 한국터널지하공간학회 논문집
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• 제16권4호
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• pp.417-430
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• 2014

도심지 내 지하공간의 효율적인 활용을 위해서 연마재 워터젯 시스템(abrasive waterjet system)을 이용한 새로운 형태의 암반굴착 공법이 개발되어 활용 중에 있다. 연마재 워터젯 시스템을 활용한 굴착(절삭) 수행 시 적정량의 연마재를 투입하고 연마재입자의 유동성을 원활하게 유지하는 것은 매우 중요하다. 본 연구에서는 실내실험을 통해 연마재 입자의 유동성과 관련된 영향인자들을 연마재 관 설치높이, 연마재 관 길이, 연마재 관 굴곡도 그리고 연마재 관 내경으로 나누어 연마재 투입량 및 유동성 수준을 평가하였다. 또한, 실험결과를 바탕으로 연마재 투입량 및 연마재 입자 유동성에 관한 최적 조건을 제시하였다. 본 연구결과를 바탕으로 향후 암반 굴착용 워터젯 공법이 도심지 내 터널, 공동구, 수직구 건설 등 다양한 지반 구조물 굴착 작업 시, 최적 연마재 투입을 위한 기초자료로 유용하게 활용될 수 있을 것으로 기대된다.

• 한국방재안전학회논문집
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• 제11권2호
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• pp.17-28
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• 2018

본 연구에서는 지반굴착 시 굴착구간 주변의 지하시설물이 지하수 흐름특성에 미치는 영향을 파악하기 위해 지하시설물의 규모와 이격거리, 지하수 동수구배 등을 고려하여 시나리오 기반으로 굴착 단계별 지하시설물의 영향을 지하수 수위 변화와 지하수 유출량 측면에서 비교 분석하였다. 그 결과 지하시설물의 규모가 증가할수록 수두차와 수두구배가 크게 발생하며 이격거리가 짧을수록 큰 수두차와 수두구배를 보인다. 모델영역의 지하수 수두구배에 따른 영향은 비교적 작은 것으로 나타났다. 또한 시나리오에 대한 지하수 유출량 분석 결과 지하시설물의 규모가 증가하거나 이격거리가 짧을수록 지하수 유출량이 감소하는 경향을 보인다. 이는 지반굴착에 따른 지하수 유동특성 분석에 있어 주변에 존재하는 지하시설물에 대한 영향 검토가 필요한 것으로 판단된다.

• Geomechanics and Engineering
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• 제29권3호
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• pp.249-258
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• 2022

A disc cutter is an excavation tool on a tunnel boring machine (TBM) cutterhead; it crushes and cuts rock mass while the machine excavates using the cutterhead's rotational movement. Disc cutter wear occurs naturally. Thus, along with the management of downtime and excavation efficiency, abrasioned disc cutters need to be replaced at the proper time; otherwise, the construction period could be delayed and the cost could increase. The most common prediction models for TBM performance and for the disc cutter lifetime have been proposed by the Colorado School of Mines and Norwegian University of Science and Technology. However, design parameters of existing models do not well correspond to the field values when a TBM encounters complex and difficult ground conditions in the field. Thus, this study proposes a series of machine learning models to predict the disc cutter lifetime of a shield TBM using the excavation (machine) data during operation which is response to the rock mass. This study utilizes five different machine learning techniques: four types of classification models (i.e., K-Nearest Neighbors (KNN), Support Vector Machine, Decision Tree, and Staking Ensemble Model) and one artificial neural network (ANN) model. The KNN model was found to be the best model among the four classification models, affording the highest recall of 81%. The ANN model also predicted the wear rate of disc cutters reasonably well.

• Geomechanics and Engineering
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• 제16권3호
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• pp.295-308
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• 2018

The excavation of twin tunnels is a process that destabilizes the ground. The stability of the tunnel lining, the control of ground displacements around the tunnel resulting from each excavation and the interaction between them must be controlled. This paper provides a new approach for replacing the costly 3D analyses with the equivalent 2D analyses that closely reflects the in-situ measurements when excavating twin tunnels. The modeling was performed in two dimensions using the FLAC2D finite difference code. The three-dimensional effect of excavation is taken into account through the deconfinement rate ${\lambda}$ of the soil surrounding the excavation by applying the convergence-confinement method. A comparison between settlements derived by the proposed 2D analysis and the settlements measured in a real project in Algeria shows an acceptable agreement. Also, this paper reports the investigation into the changes in deformations on tunnel linings and surface settlements which may be expected if the twin tunnels of T4 El-Harouche Skikda were constructed with a tunneling machine. Special attention was paid to the influence of the excavation phase shift distance between the two mechanized tunnel faces. It is revealed that the ground movements and the lining deformations during tunnel excavation depend on the distance between the tunnels' axis and the excavation phase shift.

• 터널과지하공간
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• 제33권5호
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• pp.299-311
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• 2023

TBM의 실굴진율을 향상시키기 위한 연속굴착 기술들이 개발되고 있다. 연속굴착은 설치중인 세그먼트를 제외한 나머지 세그먼트에 추력을 가해, 굴진 정지 시간을 줄이는 기술이다. 본 기술보고는 연속굴착 세그먼트에 관한 선행기술을 조사하였다. 주요 선행기술을 헬리컬 세그먼트, 육각형 세그먼트, 기존 세그먼트 방법으로 분류했다. 헬리컬 세그먼트 방법은 아직 시공사례가 없으며, 육각형 세그먼트 방법은 상용화에 성공하지 못했다. 기존 세그먼트를 이용한 연속굴착 방법은 실증에 성공했다. 해당 기술에 대한 추진잭 추력, 운영방법을 분석했다. 국내에서도 TBM 연속굴착 연구개발이 진행 중이며, 성공사례 분석을 통해 독자적인 연속굴착 방법이 개발되어야 할 것으로 판단된다.

• 화약ㆍ발파
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• 제31권2호
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• pp.32-39
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• 2013

일반적으로 장공발파 방법은 과거 대규모 채탄막장이나 댐 기초굴착, 광산 등에서 행하여져 왔으나, 최근 우리나라에서 신설되는 토목터널에서 시공 효율성 및 경제성을 목적으로 많이 실시되고 있다. 고속국도제 600호선 부산외곽 고속도로 ${\bigcirc}$공구 또한 총연장 약 8km의 4차선 대단면 도로 터널로서 Type I, II, 4.4m 장공발파를 실시하는 현장이다. 그러나 당 현장에서는 발파 후 굴진율이 약 75%에 그쳐 발파 후속작업 시간에 영향을 미치게 되고 그로 인하여 전체 작업공정 시간이 증가하여 계획된 굴진을 못하는 현상이 자주 발생되었다. 본 논문에서는 당 현장에서 위 문제를 극복하기 위하여 실시된 장공발파 공법 중 천공경과 가장 밀장전 할 수 있는 ${\phi}36mm$폭약을 적용하여 굴진효율을 향상시키고 작업공정 시간을 단축시킨 사례를 소개하고자 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1500-1505
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• 2010

The objective of this study is controlling of the large diameter Shield TBM excavation for subway tunnels. In this paper, it will focus on the selection of Shield TBM and the problems of excavation due to unusual abrasion of the Disk Cutters and the distorted Cutter Mounts, in mixed layer of soil in below and hard rock in above, and in rock layer. And also, it will be discussed that the type of ground improvement to change and repair the Disk Cutters and the distorted Cutter Mounts, Advance Rate, Cutter Torque, etc. The results of this study will be using controlling of the excavation in various large diameter Shield TBM for subway tunnels.