Abstract E08AZOY&g
Rock mass is inhomogeneous in nature. Data for underground structure designs are mainly obtained from site investigations and
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tests, but they are very limited. For this reason, uncertainty exists in the process of constructing underground structures in a rock svpWABO
mass. In the design a tunnel support pattern, the most important parameters such as advance rate and excavation method must be ](_(1
determined optimally. However, it is difficult to determine these parameters quantitatively. In addition, if these parameters are deter- z,rWj][P
mined incorrectly, unexpected risk occurs such as the decrease in the tunnel stability or economic loss due to excessive amount of glHag"(
supports. jo< sN
In this study, a methodology to determine an optimal support pattern and advance rate for the design of a tunnel is introduced s*k"-5
based on risk analysis. It can be confirmed quantitatively that the more the tunnel is supported, the higher the reliability index _; 01/V"q6
becomes and the more stable the tunnel is predicted to be. Also an optimal support pattern and advance rate can be determined cD s#5,
quantitatively by performing a risk analysis considering the construction cost and the cost of losses that can occur due to the col- >\D XA)nc
lapse of a tunnel. RAE|eTnna
2005 Elsevier Ltd. All rights reserved. C,PCU <q
Keywords: Risk analysis; Factor of safety; Monte Carlo simulation; T
