Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Estimation of Shear Wave Velocity of Weathered Granite Layer Using Nonlinear Multiple Regression Analysis; A Case Study in South Korea

비선형 다중회귀분석을 통한 국내 화강 풍화대 전단파 속도 평가에 대한 사례 연구

  • Lee, Seung-Hwan (Korea Construction Standard Center, Korea Institute of Civil Engrg. and Building Technology) ;
  • Baek, Sung-Ha (Dept. of Future Technology and Convergence Research, Korea Institute of Civil Engrg. and Building Technology) ;
  • Chung, Choong-Ki (Dept. of Civil & Environmental Engrg., Seoul National Univ.) ;
  • Kwak, Tae-Young (Dept. of Infrastructure Safety Research, Korea Institute of Civil Engrg. and Building Technology)
  • 이승환 (한국건설기술연구원 국가건설기준센터) ;
  • 백성하 (한국건설기술연구원 미래융합연구본부) ;
  • 정충기 (서울대학교 건설환경공학부) ;
  • 곽태영 (한국건설기술연구원 인프라안전연구본부)
  • Received : 2021.05.24
  • Accepted : 2021.06.15
  • Published : 2021.06.30
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Abstract

Since many geotechnical structures are constructed on a weathered granite layer, it is important to evaluate their characteristics. As a seismic design is the more important nowadays, the demands to estimate a shear wave velocity (VS) based on acceptable methods are increasing. In this study, an empirical equation predicting VS of the weathered granite layer is suggested based on the nonlinear multiple variable regression analysis whose independent variables are both SPT (Standard penetration test)-N60 and chemical weathering index. It is concluded that the accuracy of the empirical equation estimating VS of the weathered granite layer increases when it considers the chemical weathering index as an additional independent variable compared to the result of simple regression analysis using only N60.

화강 풍화대 지반은 지반구조물의 주요 지지층으로 활용되고 있으므로 화강 풍화대의 지반특성을 평가하는 것은 중요하다. 특히, 내진설계의 중요성이 부각되고 있음에 따라 지반분류 및 지반 최대 전단 탄성계수(Gmax) 평가에 활용되는 전단파 속도(VS)의 합리적인 평가의 중요성이 증가하고 있다. 본 연구에서는 국내 화강 풍화대 지층을 대상으로 표준관입시험(SPT: Standard penetration test) N60 및 채취한 시료의 화학적 풍화지수를 바탕으로 비선형 다변량 회귀분석을 수행하여 전단파 속도(VS) 추정식을 제안하였고, 기존 관련 연구결과와 비교하였다. 화학적 풍화지수를 추가적인 독립변수로 고려하여 풍화도를 고려한 경우 N60만을 사용하여 수행한 단순 회귀분석 결과에 비해 결정계수가 증가하여 전단파 속도 추정식의 정확도가 향상됨을 확인하였다.

Keywords

Acknowledgement

본 연구는 해양수산부 학술연구용역(과제명: 스마트 지반정보 관리 및 침하예측시스템 구축 연구 용역)과 케이블교량 글로벌 경쟁력 강화를 위한 전주기 엔지니어링 가설공법 개발(과제번호: 21SCIP-B119958-06) 및 서울대학교 건설환경종합연구소의 지원으로 수행되었습니다. 이에 깊은 감사를 드립니다.

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