• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.135-137
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• 2002

NATM has been generalized as a tunnelling method since the early of 1980's in Korea. But the concrete lining as the secondary supporting system based on the NATM concept has not been treated in tunnelling construction. The Purpose of this paper is to study the improvements and the problems of concrete lining in the rock tunnel

• Magazine of the Korea Concrete Institute
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• v.25 no.1
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• pp.59-63
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• 2013

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.167-168
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• 2010

This study considered applications of FRP panels as curved structural members. Also, curved GFRP panel with open cell type for tunnel lining was manufactured by pultrusion method through improving equipments.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.116-127
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• 2014

The studies were carried out to process one cycle for a day to the large section tunnel lining concrete. Climatic characteristics of the tunnel inside are changed, when the temperature of the concrete placement is low, the mold remove time is increased that the heat of hydration speed be delayed because affects the strength development, to compensate for this, after installing the curing sheet on both sides of the steel form and installation of tunnel entrance, when it comes to providing the additional heat source of $28{\pm}2^{\circ}C$ therein, it was to be achieved early strength development control standards (4.5MPa) presented as a crack control scheme or more, thus, It was able to remove after age of 14hr from mold. On the other hand, under the conditions of $10{\pm}1^{\circ}C$ that a natural curing temperature in the tunnel, it was analyzed must ensure the curing time of 36hr or more after concrete placement. Throughout this study, the concrete strength development and the temperature in the early-age concrete, it can find that reverify the curing temperature is greatly affected, even concrete fly ash is mixed 10%, if it is possible to raise the surface temperature for a predetermined time, is not a problem in the early strength development.

• Magazine of the Korea Concrete Institute
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• v.5 no.1
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• pp.62-67
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• 1993

• Magazine of the Korea Concrete Institute
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• v.19 no.1
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• pp.56-65
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• 2007

• Tunnel and Underground Space
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• v.11 no.2
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• pp.96-108
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• 2001

A concrete lining of NATM tunnel is the final product of a process that involves planning and evaluation of user needs, geotechnical investigations, analysis of ground-lining interaction, construction, and observations and modifications during construction. The designer must consider the lining in context of the many function, construction, and geotechnical requirements. Also, the loss of supporting capacity of shotcrete lining due to poor rock qualities and shotcrete erosion must be considered. The values, shapes, and estimating methods of rock load and water pressure are very different with every designers. Estimating methods of rock loads used in the design of NATM tunnel concrete lining are investigated. Structural analyses are done in various load combinations, and the member forces(moment, axial force and shear force) are compared. The adequate load combination of rock load and water pressure is proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.347-350
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• 2005

The strength level for removal of lining concrete in tunnel is increased from 2.94MPa to 4.9MPa in 2004. This result in the increase of concrete curing time, and construction time would be delayed. In this study, in order to improve the efficiency of construction cycle and satisfy the strength criterion, a curing method is adopted, which is considering the hydration heat in the lining concrete member. As a result, it is shown that the concrete curing time for form removal is about 20hrs without the adjustment of concrete mix design. And construction cycle time is not changed compared to that before the change of strength criterion.

• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.33-45
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• 2007

In this study, the blast-induced vibration effects on the structural stability of the adjacent tunnel were estimated with respect to the allowable peak particle velocity (PPV). The blasting distance from the tunnel satisfying the allowable PPV was estimated based on the analytical solutions, United States Bureau of Mines (USBM) suggestions, and the equations used in the subway in Seoul. The allowable blasting distance was estimated by using finite difference analysis (FDA) and the behavior of the concrete lining and rock bolts was examined and the stability of those was estimated during the blast. Research results show that the blast-induced vibration effects on the structural stability are negligible for the concrete lining but relatively large for the rock bolts.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.341-344
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• 2001

Fiber reinforced shotcrete(FRS) is widely used in tunnel linings, which strengthen the rock surface and reduce the loosening of the rock strata. The advantages of FRS in tunnel linings are the unsusceptibility to crack, the benefit of shotcrete strength, and the superiority of toughness. In this study, the several evaluation methods of FRS toughness were investgated experimentally, which included the ASTM beam test, EFNARC square panel test and RTA round panel test. Especially, it was examined that the round panel test could fulfill the toughness evaluation of FRS.