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Assessment of groundwater inflow rate into a tunnel considering groundwater level drawdown and permeability reduction with depth

터널굴착 중 지하수위 강하 및 깊이별 투수계수 변화를 적용한 지하수 유입량 변화 분석

  • Moon, Joon-Shik (Department of Civil Engineering, Kyungpook National University) ;
  • Zheng, An-Qi (Department of Civil Engineering, Kyungpook National University) ;
  • Jang, Seoyong (Department of Architectural Engineering, Chonnam National University)
  • 문준식 (경북대학교 토목공학과) ;
  • 쩡안치 (경북대학교 토목공학과) ;
  • 장서용 (전남대학교 건축공학과)
  • Received : 2017.01.13
  • Accepted : 2017.02.15
  • Published : 2017.03.31

Abstract

Groundwater seepage into a tunnel is one of the main causes triggering tunnel collapse and the consequent ground subsidence. Thus, it is important to estimate adequately the groundwater inflow rate and porewater pressure change during tunneling with time elapse. In current practice, Goodman's analytical solution (or image tunnel method) assuming homogeneous ground condition around a tunnel is commonly used for estimating groundwater inflow rate. However, the generally-used analytical solution for estimating groundwater inflow rate does not consider groundwater level drawdown and permeability change with depth, and the inflow rate can be overestimated in design phase. In this study, parametric study was performed in order to investigate the effect of groundwater level drawdown and permeability reduction with depth, and transient flow analysis was carried out for studying the inflow rate change as well as groundwater level and porewater pressure change around a tunnel with time elapse.

Acknowledgement

Supported by : 국토교통부

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