It is one of the most important problem for tunnel construction to estimate the final amount of rock deformation. This paper deals with the estimation of the final amount from the amount of deformation in the earlier stage of measurements at Dai-Sau-Shirasaka Tunnel which is under construction with the New Austrian Tunnelling Method. We have distinctly found that the rock behavior after excavation is constituted with viscous and plasticelastic deformations in adopting new measurement method described in this paper. Rock deformation U can be expressed by the following equations, U=UV+UEP UV=a·t UEP=C (1-e-D. L) where, UV: viscous deformation UEP: plastic elastic deformation t: elapsed time after blasting L: distance between the observation point and tunnel face a, C, D: constants
Analysis on variation of ground-water level generated by rainfall is one of foundamental points for hydrogeologic investigation. It is generally difficult to analyze the variation. Further, under construction such as tunnelling: we must also consider the variation influenced by artificial conditions. The method of analyses in the case of tunnelling still awaits settlement. We have studied the methods of analyses in tunnelling case and found out one of the methods. On the other hand we obtained many data of rainfall and well-water level in Boso tunnel area. Concerning about the hydrologic balance and the change of well-water level, we had a good result which applied to some extent. This investigation began in July, 1971 before the construction of Boso tunnel and it has been continuing for full eight years. We gained a lot of data by this investigation.