• Structural Engineering and Mechanics
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• v.45 no.3
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• pp.337-354
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• 2013

For shield TBM (Tunnel Boring Machine) tunnel lining, the segment joint is the most critical component for determining the mechanical response of the complete lining ring. To investigate the mechanical behavior of the segment joint in a water conveyance tunnel, which is different from the vehicle tunnel because of the external loads and the high internal water pressure during the tunnel's service life, full-scale joint tests were conducted. The main advantage of the joint tests over previous ones was the definiteness of the loads applied to the joints using a unique testing facility and the acquisition of the mechanical behavior of actual joints. Furthermore, based on the test results and the theoretical analysis, a mechanical model of segment joints has been proposed, which consists of all important influencing factors, including the elastic-plastic behavior of concrete, the pre-tightening force of the bolts and the deformations of all joint components, i.e., concrete blocks, bolts and cast iron panels. Finally, the proposed mechanical model of segment joints has been verified by the aforementioned full-scale joint tests.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.197-207
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• 2001

1980년대 이래 국내 터널의 시공법은 원지반의 강성을 활용한 NATM이 주를 이루고 있다. 그러나 NATM은 터널내부에 설치되는 내부라이닝의 여러 가지 문제점을 내포하고 있기 때문에 노르웨이에서는 조립식 터널 라이닝(Pre-Cast Concrete Lining, PCL)을 개발하여 현장타설 콘크리트 라이닝의 문제점을 해결하고자 하였다. 그러나 노르웨이와 같은 북유럽지역에서는 지진이 거의 발생되지 않고 있기 때문에 PCL공법 개발당시에 지진에 대한 영향을 고려하지 못하였다. 따라서 PCL공법을 국내에 도입하기 위해서는 먼저 지진에 대한 영향을 분석하여야 할 것으로 판단되므로 본 연구에서는 PCL공법 적용시 지진에 대한 안정성 평가 및 합리적 내진해석을 위한 연구를 수행하고자 하였다. PCL의 내진성능을 판단하기 위하여 먼저 국내에서 주로 많이 사용되고 있는 해석기법인 유사정적해석법과 응답스펙트럼해석법을 이용하여 분석하였으며 지반과 구조물의 상호작용에 대한 영향을 분석하기 위해 시간이력해석을 수행하여 터널심도별 PCL의 내진성능을 분석하였다. 이와 같은 방법으로 PCL의 내진해석을 수행한 결과, 부재에 발생된 응력이 허용응력 이내에서 발생되어 PCL의 내진성능을 확보된 것으로 판단된다. 또한 시간이력해석에 의한 지반-구조물 해석을 수행한 결과에 의하면 PCL의 내진성능을 확보하기 위한 터널의 최소 토피고가 터널직경에 2배 이상인 것으로 확인되었다. 또한 단순 구조물의 내진해석만으로는 PCL의 내진성능을 과소평가할 우려가 있는 것으로 나타났다.

• Journal of the Korean Geotechnical Society
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• v.16 no.6
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• pp.59-68
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• 2000

현재까지 진동이 양생중인 콘크리트에 미치는 영향을 알아보기 위해 수행된 대부분의 연구에서는 콘크리트 공시체나 콘크리트 블록에 대해 100Hz 미만의 주주파수를 가지는 충격진동이나 진동테이블을 이용한 진동을 가한 후 콘크리트의 강도 변화를 평가하는 방법이 사용되었다. 이 연구에서는 발파진동이 양생중인 라이닝 콘크리트에 미치는 영향을 알아보기 우해 실험실 충격진동 시험과 터널 현장에서의 발파진동 시험을 수행하였다. 터널발파진동과 유사한 100~300Hz의 주주파수를 가지 충격진동을 각각 재령 3, 7, 12 시간에 다한 실험실 시험결과 2cm/sec의 진동속도는 모르타르 라이닝의 P파속도를 증가시키지만, 5 cm/sec, 10cm/sec의진동의 모르타르 라이닝의 P파 속도를 감소시킬 수 있는 것으로 나타났다. 양생기간동안 2.5 cm/sec 이하의 발파진동이 가해진 양생중인 라이닝 콘크리트는 진동을 가하지 않고 양생시킨 콘크리트 공시체에 비해 압축강도가 더 큰 값을 나타내었다. 재령 5시간에 콘크리트 라이닝애 대한 소규모 시험발파로 발파진동을 가한 콘크리트 시료와 진동을 가하지 않고 터널 내에서 양생시킨 공시체에 대해 압축강도를 비교한 결과 콘크리트의 강도 및 탄성파 속도를 저하시킬 수 있는 진동수준은 3~4cm/sec 인 것 으로 나타났다.로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3797-3822
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• 2020

The inspection of cracks on the surface of tunnel linings is a common method of evaluate the condition of the tunnel. In particular, determining the thickness and shape of a crack is important because it indicates the external forces applied to the tunnel and the current condition of the concrete structure. Recently, several automatic crack detection methods have been proposed to identify cracks using captured tunnel lining images. These methods apply an image-segmentation mechanism with well-annotated datasets. However, generating the ground truths requires many resources, and the small proportion of cracks in the images cause a class-imbalance problem. A weakly annotated dataset is generated to reduce resource consumption and avoid the class-imbalance problem. However, the use of the dataset results in a large number of false positives and requires post-processing for accurate crack detection. To overcome these issues, we propose a crack detection method using a ternary classifier. The proposed method significantly reduces the false positive rate, and the performance (as measured by the F1 score) is improved by 0.33 compared to previous methods. These results demonstrate the effectiveness of the proposed method.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.195.1-195.1
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• 2011

This paper presents an experimental study on a new potential geothermal energy source obtained from tunnel structures. An "energy textile", which is a textile-type ground heat exchanger, was fabricated between a shotcrete layer and a guided drainage geotextile in the tunnel lining system. To examine the long-term thermal behavior of the energy textile, the difference in temperatures of the inlet and outlet fluid circulating through the heat exchange pipe within the energy textile was monitored using a constant-temperature water bath. Daily heat exchange rate of the energy textile during cooling operation was estimated from the measured temperatures of the inlet and outlet fluid through the energy textile. The air and ground temperature was also continuously monitored. The operation of the energy textile as a ground heat exchanger was simulated using a 3D numerical CFD model (Fluent). The thermal conductivity of shotcrete and concrete lining components and temperature variation of air in the tunnel were incorporated in the model. The numerical analysis shows a good agreement with the long-term monitoring result.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.1
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• pp.3-16
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• 2004

A finite element method is used for the force analysis of semicircular arch shaped corrugated steel plate lining. The assessment of stability and behavior for several conditions are executed from the analysis of soil-structure interaction in accordance with CHBDC (Canadian Highway Bridge Design Code, 2000). One fortieth scaled model tests were conducted on the semicircular arch lining to verify the FEM analysis results under the earth-load conditions.

• Tunnel and Underground Space
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• v.11 no.2
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• pp.146-155
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• 2001

An inverse calculation method to obtain sectional forces, axial force and flexural moment of a tunnel concrete lining was developed by utilizing convergence measurements acquired at the maintenance stage. To monitor the behavior of the lining, DOCS system was applied to a subway tunnel section. The method was proved to be effective, yielding the same results as measured forces of buried instruments. Many effects such as vibration of sensors, vibration due to test train operation, the variation of temperature and high voltage were checked and a new management scheme for tunnel maintenance was proposed.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1995.03a
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• pp.1-26
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• 1995

Key aspects of the Norwegian Method of Tunnelling (NMT) are reviewed. These include a predictive method of support design using the six-parameter Q-system of rock mass characterisation. The rock mass rating or Q-value is updated during tunnel driving. The designed tunnel support generally consists of wet process, steel fibre reinforced shotcrete combined with fully grouted, untensioned rock bolts, Even in poor rock conditions S(fr) + B usually acts as the final rock reinforcement and tunnel lining. Since it is a drained lining, it is very economic compared to cast concrete with membranes. Light, free-standing steel liners are used to prevent water affecting the runnel environment. Rock mass conditions, and hence lining design and cost estimation can be assessed by careful use of seismic surveys. Relationships between the P-wave velocity, the rock mass deformation modulus and the Q-value have recently been established, where tunnel depth, rock porosity and the uniaxial compression strength of the rock are important variables. The rock mass modulus estimate, and simple index testing of the joints, provide the key input which joints are discretely represented (either in two dimensions with the UDEC code or in three dimensions with the 3DEC code) is generally favoured compared to continuum analysis. The latter may give a misleading impression of uniformity and deformations tend to be understimated. Q-system NMT designs of S(fr) + B (fibre reinforced shotcrete and bolting) are numerically checked and adjustments made to bolt capacities and shotcrete thickness if overloading is evident around the modelled profile.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.501-506
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• 2002

Contemporary architecture calls for a wide range of surface textures and treatments. A surface compatible with the architect's design may vary from a glass-smooth finish to one requiring special sculptured ornamentation. These surfaces require many different types of form sheathing and lining. The purpose of study development new design form and made elaborateness shape. Easy to used in field that architecture finish material not used expect effective reduce of working hours, personnel expenses, architecture finish material, cost. After this, building wall apply a variety shape in concrete surface

• Journal of Industrial Technology
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• v.25 no.B
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• pp.115-120
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• 2005

Impact seismic wave method is a method for non-destructive testing of concrete structure using of stress wave which is propagate and reflected from internal flaws within concrete structure and external surface. In this study, we performed frequency domain method using impact seismic wave test for safety diagnosis of civil engineering structure. And reflection method which is used for one-dimensional target such as tunnel lining and transmission method are compared with each other.