Abstract
A design method for tunnel to be excavated by NATM in low strength ground is expected to be established. We showed previously that “the tunnel design method for minimum excavation” aimed at achieving the minimum excavation limit is effective for tunnel in low strength ground. It is not unusual, however, that low strength ground is also expansive, and the design and construction of tunnel in expansive ground inevitably depend on trial and error. The behavior of expansive ground can be regarded as creep. In this study, the applicability of the tunnel design method for minimum excavation to ground subject to creep has been investigated.
