• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2003년도 봄 학술발표회 논문집
• /
• pp.281-288
• /
• 2003

In karst formation area, the tunnel support system is an important factor for the tunnel safety during operation. This paper presents the simplified tunnel support systems to be adopt in karst formation. For the tunnel planned in the project area, karst features and the expected scenarios in the tunnel area were developed based on the results of the geological and geotechnical assessment. In order to provide specific supporting system and construction details for a wide range of possible karst features, the generalized typical support systems are developed according to the classification of karst features. In addition, the initial support systems and construction sequence for each karst feature are also presented in this paper.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(II)
• /
• pp.1059-1064
• /
• 2002

The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The load-deformation characteristics of ground and support are derived by the interaction between ground and support. The interaction between ground and support is qualitatively illustrated by a ground response curve. The behavior of an opening and the performance of support system depend upon the load-deformation characteristics of ground and support as well as of the manner and of timing of support installation. The interaction between ground and support is qualitatively illustrated by a ground response curve. The convergence-confinement method don't need the basic assumptions for a mathematical model. Also This is applicable to general tunnel. Consequently the stability of tunnel must be qualitatively investigated by a ground response curve and quantitatively adjudged by a numerical analysis for the reasonable design of tunnel.

• 한국지반공학회논문집
• /
• 제25권7호
• /
• pp.11-21
• /
• 2009

본 논문은 사질토 지반에서 천층터널의 신개념 고성능 지보시스렘을 연구하였으며 새로운 지보시스템의 메카니즘 제안과 기존의 지보시스템과의 비교 분석을 시행하였다. 새로운 지보시스템인 선지보 시스템은 터널의 굴착전에 지반을 보강해주는 효과와 터널의 지보력을 증가시켜주는 여러 가지 장점이 있다. 본 연구에서는 선지보 시스템의 시공순서를 분석하고 터널 시공시 선지보 시스템의 적용성을 검증하기위해 수치해석을 수행하였다. 신개념 지보시스템을 분석한 결과, 신개념 고성능 터널지보시스템은 천층터널에서의 적용성이 뛰어나며, 터널 입 출구, 토사터널, 연약지반에서의 적용성 또한 뛰어난 것으로 판단되어졌다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
• /
• pp.1530-1535
• /
• 2009

The cable bolt is useful underground space support system such as mining in Europe. In spite of favorable strength characteristics, past record of the cable bolt is rarely in Korea. In this study, to evaluate the mechanically characteristics the cable bolt on tunnel support system. To conduct the laboratory strength test in order to enquire material properties as reinforcement material and numerical analysis was performed considering laboratory test results. To estimate the behavior characteristics on tunnel system in which supported by the cable bolt system and compared the behavior characteristics with the rebar rock bolt system result.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2003년도 봄 학술발표회 논문집
• /
• pp.225-232
• /
• 2003

The behaviour of ground induced by tunneling of 2arch tunnels may differ from the one caused by usual type tunnels. This paper describe the behaviour created by the size of pilot tunnel and the condition on the construction method of center piller Also, loads acting on the supports of the first tunnel and the center pillar during the excavation of second tunnel is investigated by numerical analyses. The results of numerical analyses are compared to the data records of measurement results, i.e. force on the support system and ground displacement.

• Structural Engineering and Mechanics
• /
• 제86권5호
• /
• pp.621-633
• /
• 2023

Stability analysis and support system estimation of the Beheshtabad water transmission tunnel is investigated in this research. A combination approach based on the rock mass rating (RMR) and rock mass quality index (Q) is used for this purpose. In the first step, 40 datasets related to the petrological, structural, hydrological, physical, and mechanical properties of tunnel host rocks are measured in the field and laboratory. Then, RMR, Q, and height of influenced zone above the tunnel roof are computed and sorted into five general groups to analyze the tunnel stability and determine its support system. Accordingly, tunnel stand-up time, rock load, and required support system are estimated for five sorted rock groups. In addition, various empirical relations between RMR and Q i.e., linear, exponential, logarithmic, and power functions are developed using the analysis of variance (ANOVA). Based on the significance level (sig.), determination coefficient (R²) and Fisher-test (F) indices, power and logarithmic equations are proposed as the optimum relations between RMR and Q. To validate the proposed relations, their results are compared with the results of previous similar equations by using the variance account for (VAF), root mean square error (RMSE), mean absolute percentage error (MAPE) and mean absolute error (MAE) indices. Comparison results showed that the accuracy of proposed RMR-Q relations is better than the previous similar relations and their outputs are more consistent with actual data. Therefore, they can be practically utilized in designing the tunneling projects with an acceptable level of accuracy and reliability.

• 한국터널지하공간학회 논문집
• /
• 제5권3호
• /
• pp.279-289
• /
• 2003

일반적으로 석회암 공동발달지역의 터널지보는 터널의 안정성을 좌우하는 매우 중요한 요소중에 하나이다. 이를 위하여 설계단계에서 석회암 공동발달지역과 같은 불확실성 지반조건에서 터널의 지보패턴에 대하여서는 용이하게 결정 할 수 없을 것이다. 따라서 석회암 공동발달지역에서의 일반적으로 제시할 수 있는 터널지보패턴에 대한 표준화가 요구되어진다. 이 논문은 석회암공동발달지역에서의 터널지보패턴의 표준화기법에 대한 연구 결과를 제시하였다. 이 연구는 국내의 석회암 공동발달지역의 불확실한 지반조건에서의 터널지보 System에 대한 간편화 기법에 대하여 기술하였다. 특히, 석회암공동발달지역에 대한 지반의 등급화기법 뿐만 아니라 이에 따른 터널지보패턴 간편화 기법에 대하여서도 제시하였다. 또한, 석회암 공동지반등급과 지보패턴별 요구되는 보강 및 보조공법에 대하여서도 상세 서술하였다. 이 연구를 수행하기 위하여 석회암 공동이 발달되어 있는 ${\bigcirc}{\bigcirc}$지역에 계획되었던 터널에 대하여 실질적으로 설계과정을 통하여 지보패턴의 형식선정기법의 적용에 대한 연구를 실시하였다. 이 연구 결과를 통하여 향후 석회암 공동발달지역 뿐만 아니라 이와 유사지반에서의 터널지보 설계에 적용하므로써 터널기술향상을 도모할 것이다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
• /
• pp.170-180
• /
• 2008

Successful design, construction and maintenance of NATM tunnel demands prediction, control, stability guidelines, the estimation pre-improvement support system and monitoring of surface settlement, gradient and ground displacement with high accuracy. Moreover, urban NATM tunnel under difficult geotechnical conditions is important the estimation and necessary of pre-improvement support system. Various strategies have been proposed for the quantitative estimation of pre-improvement support system. This paper was investigated and analysed an assessment technique for the quantitative estimation of pre-improvement support system on underground space, as mountain and urban tunnel, in detail. The analysis performed on design and construction stage with field database using the proposed stability estimation index by many researcher including the critical strain and the apparent Young's modulus concept.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 지반공학 공동 학술발표회
• /
• pp.140-153
• /
• 2005

During the tunnel construction the major failure mode can be categorized as: tunnel failure just after the tunnel excavation without support, failure after application of shotcrete and finally failure after setting the concrete lining. The failure mode just after the tunnel excavation without support, can be further classified as : bench failure, crown failure, face failure, full face failure, failure due to weak strata and failure due to overburden. Moreover the failure after application of shotcrete is classified as heading face failure, settlement of shotcrete support, local failure of shotcrete lining and invert shotcrete. To find out the major causes of tunnel collapse, the investigation was done in case of the second phase of Seoul subway construction. The investigation results depicted that the major causes of tunnel collapse were due to the weak layer of rock/fault and sudden influx of ground water from the tunnel crown. While the investigation results of the mountain road tunnels construction have shown that the major causes of tunnel failure were inadequate analysis of tunnel face mapping results, intersection of faults and limestone cavities. In this paper some recent measurement in order to mitigate such tunnel collapse are presented

• 터널과지하공간
• /
• 제6권3호
• /
• pp.197-208
• /
• 1996

Due to the constraints in pre site-investigation for tunnel, it is essential to redesign the support structures suitable for rock mass conditions such as rock strength, ground water and discontinuity conditions for safe tunnel construction. For the selection of optimum support, it is very important to carry out the rock mass classification and in-situ measurement in tunnelling. In this paper, in a mountain tunnel designed by NATM in hard rock, the selectable system for optimum support has been studied. The tunnel is situated at Chun-an in Kyungbu highspeed railway line with 2 lanes over a length of 4, 020 m and a diameter of 15 m. The tunnel was constructed by drill & blasting method and long bench cut method, designed five types of standard support patterns according to rock mass conditions. In this tunnel, face mapping based on image processing of tunnel face and rock mass classification by RMR carried out for the quantitative evaluation of the characteristics of rock mass and compared with rock mass classes in design. Also, in-situ measurement of convergence and crown settlement conducted about 30 m interval, assessed the stability of tunnel from the analysis of monitoring data. Through the results of rock mass classification and in-situ measurement in several sections, the design of supports were modified for the safe and economic tunnelling.