• Tunnel and Underground Space
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• 제10권3호
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• pp.403-409
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• 2000

It is very important to control the final load that acts on a support system, in tunnel engineering. A reliable analysis is needed to carry out technically reasonable design and safe construction. Also, a series of procedures of construction and the rock-support interaction behavior must be considered. Most existing studies have been performed as the limited analysis based on the simplified assumption. In this study, through the analysis of a circular tunnel using a 2-D finite differential code, the rock-support interaction behaviors in the variation of rock and stress conditions are analyzed and compared with the results from the closed form solutions. Consequently, more realistic rock-support interaction curves are obtained by including the effects of initial stresses and rock condition. These curves are very useful to predict the required support pressure in the initial design stage.

• Tunnel and Underground Space
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• 제15권3호
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• pp.185-194
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• 2005

Recently, the surrounding rock mass is understood as the major support system for the tunnel constructed in the rock mass. Generally, the rock mass contains many discontinuity planes such as joints, and thus, the tunnel behavior in the rock mass is governed by the characteristics of the discontinuity planes. In this study, the behavior of tunnel in jointed rock mass is studied by model tests and numerical analyses. The results shows that the behavior of tunnel depends on the different initial stress conditions, in case that the tunnel is excavated in the ground without any joints. When a joint is located near the tunnel, the pound stress and displacement tend to increase between the tunnel and the joint.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 한국암반공학회 2001년도 춘계학술발표회 논문집
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• pp.231-245
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• 2001

경험적 암반 분류법과 운동학적 해석을 동시에 통합하여 사용할 수 있다면, 터널의 암반 상태를 분류하고 예측하는데 매우 유용할 것이다. TMR-net 분석 기법은 RMR 시스템의 평가 기준에 기초한 절리 방향 평가 기준을 설정하고, 이를 극 투영망 상의 평점 기준을 가진 활동 범위로 표현한 평사투영 중첩기법이다. 터널의 설계 및 시공 단계에 적용된 TMR-net 분석은 절리 방향의 영향과 관련된 효과적인 결과를 제공할 수 있었다.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 한국암반공학회 1995년도 정기총회 및 학술발표회
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• pp.213-219
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• 1995

터널굴착중 막장조사관찰은 막장의 안전성, 암질판정, 풍화 및 변질정도, 용수상태, 절리의 특성을 파악함으로써 시공의 합리성을 달성할 수 있는 매우 중요한 조사항목이다. 그러나 이러한 작업은 시공상 시간적제약을 받고, 조사자의 경험과 지식의 부족으로 암반에 대한 공학적 평가가 부족한 실정이다. 이러한 문제점을 극복하고, 지반조건변화에 능동적으로 대응한 터널시공을 위해서는 정확한 암반평가가 필수적이라 할 수 있다. (중략)

• Tunnel and Underground Space
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• 제10권3호
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• pp.271-277
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• 2000

쉴드터널 공법은 도시의 지하철도, 상ㆍ하수도, 전기ㆍ통신 등을 설치하기 위한 터널 건설 수단으로 활용되고 있다. 일본은 1960년경부터 도시의 근대화를 추진하면서 infrastructure를 정비하였으며 이에 따라 쉴드터널 공법의 적용이 급속히 증대하였다. 도시의 지하에 터널을 건설함에 있어 가장 중요한 것은 기존 도시구조물에 대한 영향을 최소로 줄여서 도시기능을 보전하는데 있다.(중략)

• Journal of the Korean GEO-environmental Society
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• 제18권5호
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• pp.17-26
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• 2017

Tunnel excavation in jointed rock mass induces a displacement along tunnel excavation line and its assessment is very important to ensure the stability of tunnel and a demanded space. Tunnel displacement is directly related to the deformation modulus of ground and therefore it is essential to know the value of the parameter. However, most rock masses where tunnels are constructed are generally jointed and it is difficult to find out the deformation modulus of jointed rock mass simply based on an homogeneous isotropic elastic medium because the deformation modulus is highly affected by joint condition as well as rock type. Accordingly, this study carried out extensive numerical parametric studies to examine the variation of deformation modulus in different joint conditions and rock types under the condition of tunnel excavation. The study results were compared with existing empirical relationships and also shown in the chart of deformation modulus variation in different jointed rock mass conditions.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 한국암반공학회 1999년도 정기총회 및 학술발표회
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• pp.51-54
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• 1999

현재 국내에서 시공되고 있는 터널 발파 패턴의 경우 현장암반조건과 발파조건 등 발파에 영향을 미치는 제반 여건을 정량적으로 고려한 컴퓨터에 의한 자동설계가 이루어지지 않고 있다. 그러므로 경험적이고 정성적인 방법에 의하여 터널 발파 설계가 이루어짐으로써 발파설계와 시공이 불일치하고 여굴 및 주변 손상권의 확대로 인한 터널 보강에도 영향을 미치는 등 문제점이 있다. 또한 최근에 들어와서 터널 발파 공사가 인가 근처에서 이루어 질 경우 발파진동에 의한 민원을 야기하고 있어 이를 고려한 안전 발파 설계가 절실히 요구되고 있다. (중략)

• Tunnel and Underground Space
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• 제21권6호
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• pp.439-449
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• 2011

The characteristics of rock fractures for engineering rock classification are investigated by analyzing three dimensional point cloud generated from adjusted digital images of a tunnel face during construction and the tunnel is reinforced based on the supporting pattern suggested by the RMR and the Q system using parameters extracted from those images. As results, it is possible saving time required from face mapping to tunnel reinforcing work, enhancing safety during face mapping work in tunnels and reliability of both the mapping information and selecting supporting pattern by storing the files of digital images and related information which can be checked again, if necessary sometime in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• 제6권4호
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• pp.327-343
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• 2004

During tunnel construction, ground failures often occur due to existence of weak zones, such as faults, joints, and cavities, ahead of tunnel face. It is hard to detect effectively weak zones, which can lead underground structure to fail after excavation and before supporting, by using conventional characterization methods. In this study, an enhanced analytical method of predicting weak zones ahead of tunnel face is developed to overcome some problems in the conventional geophysical exploration methods. The analytical method is based on Coulomb's and Gauss' laws with considering the characteristics of electric fields subjected to rock mass. Using the developed method, closed form solutions are obtained to detect a spherical shaped zone and an oriented fault ahead of tunnel face respectively. The analytical results suggest that the presence of weak zones and their sizes, location, and states can be accurately predicted by combining a proper inversion process with resistance measured from several electrodes on the tunnel face. It appears that the skin depth or resistivity in rock mass is affected by the diameter of tunnel face, natural electric potential and noises induced by experimental measurement and spatial distribution of uncertain properties. The developed analytical solution is verified through experimental tests. About 1800 concrete blocks of 5cm by 5cm by 5cm in size are prepared and used to model a joint rock mass around tunnel face. Weak zones are simulated ahead of tunnel face with a material which has relatively higher conductivity than concrete blocks. Experimental results on the model test show a good agreement with analytical results.

• Tunnel and Underground Space
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• 제21권6호
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• pp.450-459
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• 2011

For the purpose of evaluating the safety of rock structures such as underground caverns, tunnels and slopes, rock displacement measurement is carried out to identify the behavior of rock masses. Tapes, levels, and total stations are usually applied to the displacement measurement. These tools, however, are weighed down by many disadvantages. In this study, a new displacement measurement system by precise vision metrology was proposed for the observational design and construction method of rock structures, and then applied to a tunnel under construction. Comparisons and investigations of the measurement of the tunnel have confirmed the effectiveness and applicability of the developed measurement system.