• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.507-520
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• 2014

In this study, the surface displacement was investigated according to the various depth of cover when the tunnel excavation equipment was used in a clay soil. For this the laboratory scaled model test was carried out using the soil sample similar to the in-situ conditions. We carried out four tests according to tunnel depth(1.5D, 2.0D, 2.5D, 3.0D). The distribution of impact due to tunnelling was quantitatively analyzed in the three-dimension by measuring the surface displacement. In addition, the pattern of surface displacements was figured out.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.131-139
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• 2012

In this study, the numerical analysis has been conducted in order to check behavior characteristics of liner plate made of corrugated steel from urban small sized tunnel excavation. The analysis was conducted with five kinds of conditions like 5 m, 10 m, 15 m, 20 m and 25 m to examine the behavior characteristics of liner plate according to the depth of cover. Analysis results showed that the maximum axial stress and the maximum displacement occurs in the lower end of the member, and the maximum shear stress occurs in the upper part of the member. Also, change of displacement, stress shearing stress of liner plate based on various depth of cover are existed, but the difference is slight, and by increasing depth of cover, structural stability is gradually ensured.

• Journal of Korean Society of Steel Construction
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• v.13 no.6
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• pp.693-702
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• 2001

Ductility pipes, like corrugated steel structures, are expected to reduce its deformation when they are arranged in a row. Verifying this assumption can help make economic designs possible. Though checking the deformation of ductility pipe structures, like corrugated steel structure, decreasing deformation was found when the pipes are arranged in a row. In this way, arranging a corrugated steel structures in a row shows decreased deformation compared to corrugated steel pipes arranged in a single structure because the bedding effect restrains deformation. The deformation rates of reduction are proportionate to the diameter of the corrugated steel structure.

• Journal of the Korean Geotechnical Society
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• v.35 no.1
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• pp.43-53
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• 2019

This paper described a result of finite element analysis considering sewerage damage scale and soil depth, in order to analyze quantitatively for cavity and relaxation zone of underground due to sewerage damage. The mechanical model, which was verified by previous studies, was applied to the finite element analysis. In addition, the mechanical behavior of the soil around the sewerage damage due to the soil loss was simulated by using the forced displacement. Based on finite element analysis results, characteristics of the void ratio distribution, ground subsidence, and shear stress distribution according to sewerage damage scale and soil depth were analyzed. And then, The boundaries of the underground cavity and relaxation zone were determined by using the shear stress reduction characteristics of the ground. Also, an occurrence scope of the cavity and relaxation zone was quantitatively evaluated by the change of sewerage damage scale and soil depth.

• Journal of the Korean Geotechnical Society
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• v.28 no.8
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• pp.79-88
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• 2012

In this study, the tunnel loads acting on the concrete lining are analyzed by comparing three methods - Terzaghi table, Terzaghi formula and Ground-Lining Interaction (G.L.I) model. The tunnel loads are analyzed by FLAC 2D. And the G.L.I model is analyzed under various rock mass ratings, tunnel depths (20~80m) and in-situ stress ratios ($K_0$=0.5~2.0). Terzaghi's method can be applied only to weathered rocks and soils, and cannot reflect the effect of various tunnel depths and in-situ stress ratio. The proposed G.L.I model can not only be applied to various ground conditions, but also relieves the tunnel loads by up to 30%.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.235-253
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• 2018

Groundwater flow induced by cracks in a buried pipe causes ground loss in the vicinity of it which can lead to underground cavities and sinkhole problems. In this study, the ground collapse mechanism and the failure mode based on an aperture in the pipe located in cohesionless ground were investigated through a series of physical model studies. As the influence parameters, size of the crack, flow velocity in the pipe, groundwater level, ground cover depth and ground composition were adopted in order to examine how each of the parameters affected the behavior of the ground collapse. Influence of every experimental condition was evaluated by the final shape of ground failure (failure mode) and the amount of ground loss. According to the results, the failure mode appeared to be a 'Y' shape which featured a discontinuous change of the angle of erosion when a groundwater level was equal to the height of the ground depth. While in the case of a water table getting higher than the level of ground cover depth, the shape of the failure mode turned to be a 'V' shape that had a constant erosion angle. As the height of the ground depth increased, it was revealed that a mechanism where a vertically collapsed area which consisted of a width proportional to the ground height and a constant length occurred was repeated.

• Journal of the Korean GEO-environmental Society
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• v.5 no.1
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• pp.65-73
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• 2004

The analysis of corrugated steel pipes is depending on a second dimension frame analysis or compressed ring model. This is the analysis not to consider the behavior of soil-structure interaction. The behavior of load resistance system is varied according to the depth of cover and the spacing of corrugated steel pipes structure. Therefore, the behavior characteristic of corrugated steel pipes was confirmed through finite element analysis to consider the activity of soil-structure interaction. If soil cover is filled up to the more of optimal depth, behavior of corrugated steel pipes are similar to those of ductile steel pipes according to the earth pressure distribution and effects of traffic loads are decreased. But, If soil cover is filled up to the less of optimal depth, corrugated steel pipes can't behave completely as ductile steel pipes because the passive earth pressure acting on side of corrugated steel pipes is decreased according to the decrement of vertical earth pressure, and the traffic loads influence on the section forces is increased, so that the traffic loads dominated the behavior of corrugated steel pipes.

• Magazine of korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.17-27
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• 2023

• Journal of the Korean GEO-environmental Society
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• v.7 no.3
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• pp.55-68
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• 2006

This paper studies the moment equations in the 2000 Canadian highway bridge code(CHBDC) for soil-steel box structures, which are applicable to the span less than 8m. Finite element analyses carried out for soil-steel box structures having spans of 3-12m using the deep corrugated steel plates under three construction stages; backfill up to the crown, backfill up to the cover depth, and live loading. The coefficients of moment equations are newly proposed based on the results of numerous finite element analyses considering various design variables, such as span length, soil depth, backfill conditions. The validity of the proposed coefficients in the moment equations of the 2000 CHBDC is investigated by the comparison with the existing coefficients and numerical results of finite element analyses. The comparisons show that the moments of the 2000 CHBDC give good predictions for the span less than 8m, but underestimate for the span greater than 8m, whereas the proposed moments give good estimates of numerical results for the spans of 3-12m.

• Journal of the Korean Geotechnical Society
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• v.17 no.6
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• pp.173-180
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• 2001

This research is aimed at investigating the dynamic response of cut-and-cover tunnel to seismic waves. We carried out shaking table test which is used a 1/40-scale(the width of prototype tunnel is about 14.2m, the height is about 8.5m) model for this research, and we analyzed the effect of depth of tunnel and slope of the ground in relation to the dynamic responses of tunnel. As a result of the test, the stress and acceleration along the tunnel decreased accordingly to the depth of increment, and this phenomenon is caused by the increase of the confining effect of ground. Also, the dynamic responses of tunnel showed a tendency to rise according as ground declined gently. In comparison the result of shaking table test with that of structural analysis on ordinary condition, we conclude that seismic waves do not affect cut-and-cover tunnel when the depth of tunnel is over the diameter of tunnel.