• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.1
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• pp.77-86
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• 2006

Although the adverse critisism have been continued that the concrete lining need or not, most tunnel engineer agree that the concrete lining needs to increase the tunnel safety To establish the concrete lining's quality improvement method, we grasp the basic problems in lining construction process and propose the lining construction methods to increase the concrete quality This paper present a reason of initial crack occurrence in the large section tunnel (4 lane wide span tunnel), lining and an improved method for crack minimization in construction process. It is also verified verify that the proposed method can give qualified concrete lining by carrying out the concrete injection model test and the numerical analysis of concrete flow.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.15-23
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• 2009

This research area is a greate section of triple tunnels that passes through the fault fractured zone the in the granite area. In this area, tunnel section, pillar width and overburden height are changed consecutively due to declivity of 1 : 4.5 and slope formation of upper part as changed section. That is, stability estimation for each section varying pillar width can be conducted because tunnel diameter changes gradually from 0.5D to 1.0D according to distance of pillar width. We have estimated the stability of pillar width in triple tunnels with monitoring value, and compared the stability with results of numerical analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.4
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• pp.335-341
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• 2005

In construction of a large cross section NATM tunnel, to keep the tunnel face stability by the ground itself bench cut method is commonly used. In order to necessity of partial face excavation method, we have to look for more enhanced method that can maintain better stress intensity. This paper presents a stress distribution of the Center Diaphragm Method from the partial face excavation methods, with the numerical analysis, and induced the optimal face distance, which is minimizing stress concentration and the optimal excavation step. Commerical 3 dimensional continuum analyzing FLAC-3D Ver. 2.1 program is used for the analysis. Analyses were performed to investigate ground behavior for tunnels with variable bench-length varying from 2m to 40m.