Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Reinforcing Effect of a Soil Nailing on Plane Failure of a Slope by Comparing Finite Difference Analysis with Limit Equilibrium Analysis

유한차분해석과 한계평형해석의 비교를 통한 평면파괴 사면 쏘일네일링 보강효과 연구

  • 유광호 (수원대학교 토목공학과)
  • Received : 2013.12.24
  • Accepted : 2014.07.14
  • Published : 2014.11.30
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Abstract

It is very important to design and construct slopes safely because damage cases are increasing due to slope failure. Recently, Limit Equilibrium Method (LEM) based programs are commonly used for slope designs. Though LEM can give factors of safety through simple calculation, it has a disadvantage that the sliding surface should be assumed in advance. On the other hand, the use of Finite Difference Method (FDM) is increasing since the factor of safety can be easily estimated by using shear strength reduction technique. Therefore the purpose of this study is to present a reasonable slope design methodology by comparing the two commonly used analysis approaches; LEM and FDM. To this end, the reinforcement effects of the two methods were compared in terms of the support pattern of soil nailing reinforced in the section where plane failure is anticipated. As a result, the reinforcement effects by nail angle and nail spacing turned out to be equal. Also it was found that the factor of safety increased in LEM, but not changed in FDM when the nail length increased.

사면파괴로 인한 피해사례가 늘어남에 따라 사면을 안전하게 설계하고 시공하는 것은 대단히 중요하다. 현재 실무에서 주로 사용되는 한계평형해석은 간단한 계산에 의해 안전율을 산정할 수 있지만 활동면을 미리 가정한다는 단점이 있다. 한편 유한차분해석 시 전단강도감소기법을 이용하여 안전율 산정이 용이해짐에 따라 설계 시 이용되는 빈도가 점차 증가하고 있다. 따라서 본 연구에서는 두 가지 해석방법의 비교를 통해 합리적인 쏘일네일링 설계방안의 제안을 목적으로 한다. 이를 위해 평면파괴 예상구간에 쏘일네일링 보강 시 보강패턴에 따른 보강효과를 비교해보았다. 그 결과 네일의 각도와 간격에 따른 보강효과는 동일하게 나타났다. 하지만 네일 길이가 증가함에 따라 한계평형해석의 경우 안전율이 증가하였지만 유한차분해석의 경우 안전율의 변화가 없었다.

Keywords

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