한국지반공학회논문집 (Journal of the Korean Geotechnical Society)

한국지반공학회 (Korean Geotechnical Society)
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강우 침투로 인한 불포화 사면 붕괴의 유효응력 해석

An Effective Stress Analysis of Unsaturated Slope Failures by Rainfall Infiltration

  • 이영휘 (영남대학교 건설시스템공학과) ;
  • 오세붕 (영남대학교 건설시스템공학과) ;
  • 진인철 (영남대학교 건설시스템공학과) ;
  • 김준우 (건일엔지니어링) ;
  • 박영목 (영남대학교 건설시스템공학과)
  • 투고 : 2013.10.08
  • 심사 : 2013.11.28
  • 발행 : 2013.12.31
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초록

불포화 사면에서는 강우시 침투가 일어나고 포화가 됨에 따라 불안정해진다. 불포화토의 유효응력의 관점에서는, 모관흡수력이 감소하면 유효응력이 감소하고 동시에 전단강도도 감소하여 사면 안정성이 저해된다. 본 연구에서는 불포화토의 유효응력을 흡수응력으로 기술하는데 초점을 둔다. 그리고 유한요소응력장에서 안전율을 계산하여 실제 사면의 붕괴를 시뮬레이션한다. 하동 및 포항지역의 풍화토 지층에 대하여 실내실험을 수행하여 불포화 물성을 분석하였다. 그리고 불포화 사면의 침투 해석을 수행하고 응력해석과 안정해석을 통하여 실제 붕괴를 재현하였다. 따라서 불포화 유효응력 원리에 근거하여, 실제 사면의 안정성을 성공적으로 평가할 수 있었다. 유효응력 개념이 강우 침투를 고려한 사면 설계의 실무에 적용될 수 있음을 입증하였다.

Unsaturated slopes experience infiltration during rainfall and become unstable when saturated. On the viewpoint of unsaturated effective stress, as matric suction decreases, both effective stress and shear strength decrease, which declines slope stability consequently. This study is focused on describing effective stress based on suction stress. The actual slope failures are simulated to calculate factors of safety in the field of finite element stress. In the residual soils of Hadong and Pohang, unsaturated properties are evaluated by laboratory tests. For unsaturated slopes, analyses of infiltration, stress and stability were performed to simulate actual failures. Based on unsaturated effective stress principle, the stability of actual slopes could be evaluated successfully. It is verified for the effective stress concept to be applicable to the engineering practice on slope design which considers infiltration by rainfall.

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참고문헌

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