Abstract [laX~(ND{
Rock mass is inhomogeneous in nature. Data for underground structure designs are mainly obtained from site investigations and **YNR:#Y
tests, but they are very limited. For this reason, uncertainty exists in the process of constructing underground structures in a rock H+2J.&Ch
mass. In the design a tunnel support pattern, the most important parameters such as advance rate and excavation method must be PZA;10z
determined optimally. However, it is difficult to determine these parameters quantitatively. In addition, if these parameters are deter- $j}sxxTT
mined incorrectly, unexpected risk occurs such as the decrease in the tunnel stability or economic loss due to excessive amount of =09j1:''<d
supports. *DoE Dw
In this study, a methodology to determine an optimal support pattern and advance rate for the design of a tunnel is introduced 7e#|=e
*I!
based on risk analysis. It can be confirmed quantitatively that the more the tunnel is supported, the higher the reliability index {_MU0=7c\
becomes and the more stable the tunnel is predicted to be. Also an optimal support pattern and advance rate can be determined zT+yZA.L
quantitatively by performing a risk analysis considering the construction cost and the cost of losses that can occur due to the col- cfe[6N
lapse of a tunnel. skP_us ~
2005 Elsevier Ltd. All rights reserved. 1J *wW# e
Keywords: Risk analysis; Factor of safety; Monte Carlo simulation; T
