Abstract
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
