Abstract &3Ry0?RET
Rock mass is inhomogeneous in nature. Data for underground structure designs are mainly obtained from site investigations and 6 \?GY
tests, but they are very limited. For this reason, uncertainty exists in the process of constructing underground structures in a rock ,`!>.E.
mass. In the design a tunnel support pattern, the most important parameters such as advance rate and excavation method must be ly`\TnC
determined optimally. However, it is difficult to determine these parameters quantitatively. In addition, if these parameters are deter- 5SEGV|%
mined incorrectly, unexpected risk occurs such as the decrease in the tunnel stability or economic loss due to excessive amount of # AH gY.
supports. LEg ?/!LIT
In this study, a methodology to determine an optimal support pattern and advance rate for the design of a tunnel is introduced l0r^LK$
based on risk analysis. It can be confirmed quantitatively that the more the tunnel is supported, the higher the reliability index kq*IC&y
becomes and the more stable the tunnel is predicted to be. Also an optimal support pattern and advance rate can be determined B{K_?ae!
quantitatively by performing a risk analysis considering the construction cost and the cost of losses that can occur due to the col- U!jRF
lapse of a tunnel. g;~$xXn
2005 Elsevier Ltd. All rights reserved. eIj2(q9
Keywords: Risk analysis; Factor of safety; Monte Carlo simulation; T
