Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
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Behavioral Characteristics and Safety Management Plan for Fill Dam During Water Level Fluctuation Using Numerical Analysis

수치해석을 이용한 수위변동시 필댐의 거동특성 및 안전관리방안

  • Jung, Heedon (Department of Regional Infrastructure Engineering, Kangwon National University) ;
  • Kim, Yongseong (Dept. of Regional Infrastructure Engineering, Kangwon National University) ;
  • Lee, Moojae (Dept. of Regional Infrastructure Engineering, Kangwon National University) ;
  • Lee, Seungjoo (Dept. of Regional Infrastructure Engineering, Kangwon National University) ;
  • Tamang, Bibek (Department of Regional Infrastructure Engineering, Kangwon National University) ;
  • Heo, Joon (Rural Research Institute, Korea Rural Community Corporation) ;
  • Ahn, Sungsoo (Korea Rural Community Corporation)
  • Received : 2021.02.19
  • Accepted : 2021.03.22
  • Published : 2021.03.30
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Abstract

In this study, the behavioral characteristics of the fill dam were analyzed during water level fluctuations through a numerical analysis model, and the reservoir safety management plan was prepared. The variation in plastic deviatoric strain, horizontal displacement, stress path, pore water pressure, etc., due to elevation of water level in the upper and lower sides of shell and core were analyzed using numerical analysis software, viz. GTS NX and LIQCA. The analysis results manifest that as the water level in the dam body increases rapidly, the pore water pressure and displacement also increase quickly. It was found that the elevation of the water level causes an increase in pore water pressure in the dam body as well as an increase in the saturation of the dam body and decreased effective stress. It is considered that this type of dam behavior can be the cause of the reduction of strength and stiffness of the dam. Also, it is assumed that the accumulated plastic deviatoric strain due to the deformation of the dam body caused by water infiltration causes an increase in displacement. Based on these experimental results and the results of analyses of the existing reservoir safety diagnosis techniques, an improvement plan for dam safety diagnosis and evaluation criteria was proposed, and these results can be used as primary data while revising dam safety diagnosis guidelines.

본 연구에서는 수치해석모형을 통하여 수위변동시 필댐의 거동 특성을 분석하고 저수지의 안전관리 방안을 고찰하였다. 수치해석 프로그램(GTS NX 및 LIQCA)을 이용하여 필댐의 상·하류측 Shell 및 Core에서 수위승강에 따른 소성전단변형률, 수평변위, 응력경로, 간극수압 등을 분석하였다. 제체의 거동을 분석한 결과, 제체 내의 수위가 빠른 속도로 상승하면 간극수압 및 변위 또한 급격하게 증가하는데, 수위의 상승은 제체 내의 간극수압 증가와 제체의 포화도 증가를 유발하며, 제체의 유효응력을 감소시키는 것으로 나타났다. 이러한 수위승강 시 필댐의 거동 특성은 제체의 강도 및 강성이 저하되는 원인이 되고, 침투로 인해 발생하는 제체의 변형에 의해 소성전단변형률이 축적되어 변위 증가를 유발하는 것으로 판단된다. 본 연구를 통해 저수지의 정밀안전진단 상태평가 기준 개선안을 제안하였으며, 향후 저수지 안전진단지침 개정안 마련 시 기초자료로 활용될 수 있을 것으로 판단된다.

Keywords

Acknowledgement

This study was supported by 2016 Research Grant from Kangwon National University. (No. 520160417)

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