Time-dependent deformation occurs when geo-materials are under an applied
load; this may lead to additional deflection of a tunnel structure and the
stress redistribution in the surrounding rock, shotcrete lining and rock bolt
support system over time. A better understanding of this creep behaviour can
improve the reliability of design, construction and maintenance of tunnels.
Hence, the present investigation was carried out on the time-dependent
properties of rock, shotcrete and the combined tunnel support system.
Tunnels constructed in different ground conditions were modelled. The closure
changes of the tunnel with time and the redistribution of stress in the
surrounding rock, shotcrete lining and rock bolts due to the creep deformation
were analysed. Results of the present analysis were compared with the results
from the commercial program ABAQUS.