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Safety Evaluation of Agricultural Reservoirs due to Raising Embankment by Field Monitoring and Numerical Analysis

현장계측과 수치해석에 의한 농업용저수지 제체의 안정성 평가

  • Lee, Kwang Sol (Technical Review and Quality Management Institute, Korea Rural Community Corporation (KRC)) ;
  • Lee, Dal Won (Dept. of Agricultural and Rural Engineering, Chungnam National University) ;
  • Lee, Young Hak (Dept. of Agricultural and Rural Engineering, Chungnam National University)
  • Received : 2016.01.21
  • Accepted : 2016.03.03
  • Published : 2016.03.31

Abstract

This study analyzed pore water pressure, earth pressure and settlement through field monitoring on the project site in which raising embankments are being built through backside extension, and compared the behaviors of seepage analysis, slope stability analysis and stress-strain during flood water levels and rapid drawdown under steady state and transient condition. The variation of pore water pressure showed an increase during the later period in both upstream and downstream slope, with downstream slope more largely increased than upstream slope overall. The variation of earth pressure increased according to the increase of embankment heights, while the change largely showed in the upstream slope, it was slowly increased in the downstream slope. The settlements largely increased until 23 m as embankment heights increased, and showed very little settlement overall. Under a steady state and transient conditions, the seepage quantity per day and leakage quantity per 100 m of embankment against total storage were shown to be stable for piping. The hydraulic gradient at the core before and after raising embankments was greater than the limit hydraulic gradient, showing instability for piping. The safety factor of upstream and downstream slopes were shown to be very large at a steady state, while the upstream slopes greatly decreased at a transit conditions, downstream slopes did not show any significant changes. The horizontal settlements, the maximum shear strain and stress are especially distributed at the connecting portion of the existing reservoir and the new extension of backside. Accordingly, the backside extension method should be designed and reinforced differently from the cases of other types reservoirs.

Keywords

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