• 한국지반환경공학회 논문집
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• 제12권9호
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• pp.35-45
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• 2011

본 연구에서는 터널 지보재의 거동을 전기펄스를 이용한 계측 시스템인 TDR센서를 이용하여 파악하고자 하였다. 터널 지보재의 거동을 파악하기 위해 먼저 구리테이프를 TDR센서의 계측재료로 이용하여 터널 지보재에 설치하기 위한 제작기법에 대해 연구하였다. 그 결과 구리테이프의 상부에 유리테이프, 하부에 스티로폼+전자파 차단시트를 설치했을 때 TDR센서의 민감도가 적절했고 노이즈 발생량도 적었다. PVC파이프 터널모형단면을 통해 단면의 강성과 지점 조건에 따라 데이터의 형태가 어떠한 경향을 나타내는 지 확인할 수 있었다. 이는 실제 현장에 구리테이프를 이용하여 터널 지보재의 거동을 정확히 파악하기 위해서는 지보재의 강성과 지점 조건을 현장과 동일하게 하여야 함을 알 수 있었다. TDR데이터와 유한요소해석과의 비교를 통해 TDR센서를 이용하여 터널의 거동을 파악할 수 있음을 알 수 있다. TDR데이터를 통해 지보재의 변형을 정성적으로 파악할 수 있고, 응력과 변형률 관계를 통해 지보재의 부재력까지 파악할 수 있을 것으로 기대된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1995년도 가을 학술발표회 논문집
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• pp.17.1-24
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• 1995

In tennelling lattice girders have basically the same function as steel arch supports. They serve as elements of temporary lining and in some cases also as part of the permanent lining. Also lattice girders are closely connected with that of the shotcreting lining technique. This paper presents the results of modelling test for analysing shorcrete rebound, shotcreting time and finding void spaces using the aretificial tunnel wall which consist of wood to evaluate the site applicability of lattice girders for tunnel support. Test results indicate that in case of using lattice girders as a tunnel support material, shotcrete rebound, shotcreting time and occurrence of void spaces are relatively reduced comparing to H-beam steel rib. And we can get some informations ths lattice girder has various advantages when we use it as one of tunnel support materials.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1991년도 추계학술발표회 논문집 지반공학에서의 컴퓨터 활용 COMPUTER UTILIZATION IN GEOTECHNICAL ENGINEERING
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• pp.123-132
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• 1991

The GEOKST program was used to solve the tunnel example problem. The package can solve such geotechnical problem as excavation, embankment, foundations, etc., in which the soil can be modeled by various elastoplastic geomaterial models. The main objective was to consider the effects of excavation depth to the face of the tunnel on the stability of the ground and support system. Depended on the strength of the ground materials, the limit excavation depth without any support system could be established by analyzing three-dimensional excavation problem. In this given example problem, the strengths of the ground materials were enough for the stability of the tunnel without any support system up to fairly deep excavation and the maximum tunnel section displacement was stabilized as the excavation proceed. The asymptotic value was approximately the same as that of the plane strain analysis. Thus, assuming the plain strain condition and simulation the actual excavation procedure, the maximum tunnel section displacement was caculated after final step. The maximum calculated displacement occured at the top section of the tunnel geometry and was about 8mm.

• 한국구조물진단유지관리공학회 논문집
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• 제13권4호통권56호
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• pp.107-115
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• 2009

70~80년대에 다수의 고속도로 건설과 함께 축적된 고속도로 터널에 대한 설계 및 시공기술에 비하여 철도터널의 설계는 최근들어 활발하게 이루어지고 있는 상황이다. 따라서 고속도로 터널과 철도 터널의 비교시에는 다소간의 시간적인 차이가 있는 것이 사실이다. 본 논문에서는 서로 비슷한 굴착단면적을 갖고 있으나 단면형상에서 차이를 나타내는 고속도로 2차로 자연환기터널과 선로중심간격 4.3m의 복선철도 터널에 대해 동일한 조건하에서 지보재를 설치하지 않은 경우와 지보재를 설치한 경우에 대해 수치해석을 수행하여 단면형상 차이에 따른 터널 주변암반에 발생하는 주응력크기 및 축차응력 비교를 통한 터널의 안정성을 비교 분석하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.87-92
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• 2000

In excavation of tunnels especially located in shallow depth, it is not rare to meet geological change in excavation progress worse than expected in the initial design stage. This paper present a case study on the re-design of excavation and support system of a shallow tunnel under construction where it meets the unexpected bad geological condition during excavation. The detailed geological investigation shows that the rock mass is heavily weathered and fractured with RMR value less than 20. Considering this geological condition, the design concept is focused on the reinforcement of the ground preceding the excavation of tunnel. Two design patterns, LW-grouting & forepoling with pilot tunnelling method and the steel pipe reinforced grouting method, are suggested. Numerical analysis by FLAC shows that these two patterns give the tunnel and roof ground stable in excavation process while the original design causes severe failure zone around the tunnel and floor heaving. In point of the mechanical stability and the degree of construction, the steel pipe reinforced grouting technique proved to be good for the reinforcement of heavily fractured rock mass in tunnelling. This assessment and design process would be a guide in the construction of tunnels in heavily weathered and fractured rock mass situation.

• 터널과지하공간
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• 제7권1호
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• pp.1-12
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• 1997

Engineering rock mass classification is extensively used to determine the reasonable support system throughout the tunneling process in the field. Selection of support system based on the results of engineering rock mass classification is simple and straight-forward. However, this method cannot consider the effect of in-situ stresses, mechanical properties of support material, and support installation time on the behavior or rock-support system To handle the various conditions encountered in the underground excavation sites rock-support system. To handle the various conditions encountered in th eunderground excavation sites rock-support interaction program has been developed. This program can analyze the interaction between rock mass and support materials and also can simulate the tunnel excavation-support insstallation process by controlling the support installation time and the stiffness of support system. Practical applicability of this program was verfied by comparing the results of support design to those from rock mass classification for virtual underground excavation at the drilling site KD-06 in Geoje island.

• 한국건설순환자원학회논문집
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• 제8권4호
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• pp.545-552
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• 2020

본 연구에서는 터널 지보재로서의 역학적 성능을 충분히 발휘하면서 시공성 및 안정성을 보다 향상시키기 위한 목적으로 개발된 숏크리트용 섬유 그물망 일체형 터널 지보시스템의 지보 성능을 4점 굽힘 시험, 2차원 유한요소해석 및 단면 해석을 통해 평가하였다. 4점 굽힘 시험을 통한 휨 성능 평가 결과, 섬유 그물망 보강 숏크리트의 경우, 강섬유 보강 숏크리트와는 달리 섬유 그물망의 인장 성능이 발휘되면서 균열 이후에도 하중이 지속적으로 증가하는 결과가 나타났다. 또한, 지반 조건에 대한 터널 단면 구조 해석, 섬유 그물망 및 강섬유 보강 숏크리트의 단면 해석 결과, 섬유 그물망 보강 숏크리트의 타설 두께를 기존에 비해 감소시켜도 충분한 지보 성능이 발휘될 수 있는 것으로 나타났다. 추가적으로, 이와 같은 결과를 종합하여, 암반등급 3등급 지반 중 보다 높은 안정성을 요구하는 시공 구간에 효율적으로 적용될 수 있는 숏크리트용 섬유 그물망 일체형 터널 지보시스템의 지보패턴이 제안되었다.

• Geomechanics and Engineering
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• 제36권1호
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• pp.51-69
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• 2024

Currently, composite lining mountain tunnels in China are generally classified based on the [BQ] method for the surrounding rock grade. Increasingly, tunnel field construction is replicated indoors for scale down model tests. However, the development of analogous materials for model tests of composite lining tunnels with different surrounding rock grades is still unclear. In this study, typical Class III and V surrounding rock analogous materials and corresponding composite lining support materials were developed. The whole processes of excavation-support dynamics of the mountain tunnels were simulated. Data on the variation of deformations, contact pressures and strains on the surrounding rock were obtained. Finally, a comparative analysis between model tests and numerical simulations was performed to verify the rationality of analogous material development. The following useful conclusions were obtained by analyzing the data from the tests. The main analogous materials of Class III surrounding rock are barite powder, high-strength gypsum and quartz sand with fly ash, quartz sand, anhydrous ethanol and rosin for Class V surrounding rock. Analogous materials for rockbolts, steel arches are replaced by aluminum bar and iron bar respectively with both shotcrete and secondary lining corresponding to gypsum and water. In addition, load release rate of Class V surrounding rock should be less than Class III surrounding rock. The fenestration level had large influence on the load sharing ratio of the secondary lining, with a difference of more than 30%, while the influence of the support time was smaller. The Sharing ratios of secondary lining in Class III surrounding rock do not exceed 12%, while those of Class V surrounding rock exceed 40%. The overall difference between the results of model tests and numerical simulations is small, which verifies the feasibility of similar material development in this study.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.860-865
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• 2005

In Korea, NATM (New Austrian Tunneling Method) has widely been used in order for constructing tunnels. The major support materials of the method are the shotcrete and rock bolt together with the arch-shaped tunnel section, which ensure the inherent strength of the rock masses. One of the most important features of the method is the feedback system between tunnel analyses and measurements, such as tunnel displacement and support stresses. This study, therefore, attempts to examine the difference in displacement and stresses between numerical results. and measurements in order for more practical design and construction of tunnels.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.759-766
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• 2002

In the paper the authors describe the development of ITIS(Intelligent Tunneling Information System) for the Purpose of applying the 3D visualization technique, GIS, AI(Artificial Intelligence) to tunnel design and construction. VR(Virtual Reality) and 3D visualization techniques are applied in order to develope the 3D model of characteristics and structures of ground and rock mass. Database for all the materials related to site investigation and tunnel construction is developed using GIS technique. AI technique such as fuzzy theory and neural network is applied to predict ground settlement, decide tunnel support method and estimate ground and rock mass properties according to tunnel excavation steps. ITIS can help to inform various necessary tunnel information to engineers quickly and manage tunnel using acquired information based on D/B.