• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.5
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• pp.395-411
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• 2011

This paper presents a new supporting system using steel ribs. In order to perform this research, experimental and numerical studies were performed. In the experimental study, the scaled model tests for the new supporting system consisting of the steel ribs and rock bolts were carried and compared with the conventional existing supporting system. The numerical simulation was carried out to evaluate the new supporting system to verify the experimental results. It was found that the new tunnel supporting system will reduce the tunnel damage.

• Journal of the Korean Geotechnical Society
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• v.25 no.7
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• pp.11-21
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• 2009

This paper presents a new high-performance supporting system of the shallow tunnel. In order to perform this research the mechanism of new supporting system is suggested and compared with the conventional existing supporting system. It is found that the new supporting system as pre-support system has several advantages such as improvement of ground before tunnel excavation and increment of capacity of the tunnel support. The construction procedures of this supporting system are also reviewed. In addition, the numerical simulation is carried out to evaluate the new supporting system. It is found that the new high-performance supporting system is very applicable in shallow depth tunnel such as portal area, tunnel in soil and weak zone, and so on.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.505-522
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• 2013

Previously, a new concept of indexing methodology has been proposed for quantitative assessment of tunnel collapse hazard level at each tunnel face with respect to the given geological data, design condition and the corresponding construction activity (Shin et al, 2009a). In this paper, 'linear' model, in which weights of influence factors are invariable, and 'non-linear' model, in which weights of influence factors are variable, are taken into account with some examples. Then, the 'non-linear' model is validated by using 100 tunnel collapse cases. It appears that 'non-linear' model allows us to have adapted weight values of influence factors to characteristics of given tunnel site. In order to make a better understanding and help for an effective use of the system, a series of operating processes of the system are built up. Then, by following the processes, the system is applied to a real-life tunnel project in very weak and varying ground conditions. Through this approach, it would be quite apparent that the tunnel collapse hazard indices are determined by well interlinked consideration of face mapping data as well as design/construction data. The calculated indices seem to be in good agreement with available electric resistivity distribution and design/construction status. In addition, This approach could enhance effective usage of face mapping data and lead timely and well corresponding field reactions to situation of weak tunnel faces.