• Title/Summary/Keyword: NTNU estimation model

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An analysis of excavation cycle time for Korean tunnels and the comparison with the Standard of Construction Estimate (국내터널 굴착 사이클타임에 대한 분석결과와 표준품셈과의 비교)

  • Kim, Yangkyun;Kim, Hyung-Mok;Lee, Sean S.
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.137-153
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    • 2019
  • Estimating tunnel construction time and costs are the most fundamental part of a tunnel project planning, which has been generally assessed on a deterministic basis until now. In this paper, excavation cycle time was investigated for two road tunnels and one subway tunnel, and the results were compared with the Standard of Construction Estimate (SE), which is made for the estimation of construction time and cost in a design stage. The results show that the difference in cycle time between SE and actual cycle time is 50%, 7% and 31% respectively for the three tunnels, which means that SE does not reflect practical operation time. The major reasons of the difference are skilled level of tunneling workers, the change of operation sequences for more effective operations, much more complicated working atmosphere in a tunnel than the assumption of SE etc. Finally, even though the results can not be generalized since investigated tunnels are only 3, but it is thought that SE needs to be upgraded into the model able to consider quite common situations through additional tunnel investigation and studies in the future.