ABSTRACT
This paper presents design and construction aspects of recent large underground construction projects executed in Korea. Two projects were presented; one for an underground low and intermediate level nuclear waste repository construction project and the other for a large diameter railway tunnel construction project executed under a domestic airport. A number of design and construction issues were brought up when executing these projects due largely to difficult ground conditions and construction constraints. The first case history illustrates implementation of large scale finite element computing for design of the underground nuclear waste repository which involved with construction of six mega size underground silos in complex, unfavorable geological conditions with high initial in-situ stresses. The second case history involves construction of the railway tunnel directly under the domestic airport, where excessive settlements occurred due to inappropriate groundwater control during tunnelling, which eventually raised significant concerns over operational safety of the airport facilities situated in the settlement affected area. This paper presents details of the design and construction aspects of the two case histories together with practical implications of the findings.
