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국내 화강 풍화대 지반의 표준관입시험 N 값과 프레셔미터시험 결과의 상관관계에 대한 사례 분석

Case Study of Correlation between the SPT-N Value and PMT Results Performed on Weathered Granite Zone in Korea

  • 이승환 (서울대학교 건설환경공학부) ;
  • 백성하 (한국건설기술연구원 미래융합연구본부) ;
  • 송영우 (서울대학교 건설환경종합연구소) ;
  • 정충기 (서울대학교 건설환경공학부)
  • Lee, Seung-Hwan (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Baek, Sung-Ha (Dept. of Future Technology and Convergence Research, Korea Institute of Civil Engrg. and Building Technology) ;
  • Song, Young-Woo (Institute of Construction and Environmental Engrg., Seoul National Univ.) ;
  • Chung, Choong-Ki (Dept. of Civil & Environmental Engrg., Seoul National Univ.)
  • 투고 : 2019.08.19
  • 심사 : 2019.11.05
  • 발행 : 2019.12.31

초록

국내 다수의 지역에 분포하는 화강 풍화대 지반은 지반구조물의 주요 지지층으로 활용되고 있으므로 화강 풍화대의 지반특성을 평가하는 것은 중요하다. 풍화대 지반은 실내시험을 위한 불교란 시료를 채취하는 것이 어렵기 때문에 일반적으로 표준관입시험(SPT: Standard penetration test)을 통해 지반특성을 평가하고 있다. 프레셔미터시험(PMT: Pressuremeter test)은 풍화대 지반의 응력 - 변형률 거동을 신뢰도 높게 평가하는 대표적인 현장시험이지만 소요 시간과 비용의 제약으로 제한적인 시험만을 수행하고 있다. 본 연구에서는 화강 풍화대에서 수행된 SPT-N60 값과 PMT 결과의 상관성 분석을 수행하였으며, N60 - Em(Em: Pressuremeter modulus)과 N60 - PL(PL: Limit pressure) 관계식을 제안하였고 선행 연구 결과와 비교 분석하였다.

Weathered granite zone exists in most regions of Korea and it is often used as a bearing stratum of geotechnical structures. So it is very important to estimate the characteristics of weathered granite zone. SPT (Standard penetration test) is usually performed to investigate the characteristics of the weathered zone because undisturbed samples suitable for laboratory testing are hardly retrieved. PMT (Pressuremeter test) can reliably evaluate the in situ stress-strain behavior, but it is rarely conducted because of their high cost and time-consuming procedure. In this study, the correlation between the SPT-N values and the PMT results, obtained from the weathered granite zone, was analyzed. Empirical equations for pressuremeter modulus (Em) and limit pressure (PL) were suggested and compared with the previous research.

키워드

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