Proceedings of the Korean Geotechical Society Conference (한국지반공학회:학술대회논문집)

Korean Geotechnical Society (한국지반공학회)
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Determination of Resistance Factors for Drilled Shaft Based on Load Test

현장타설말뚝의 주면지지력 저항계수 산정

  • Kim, Seok-Jung (Dept. of Civil and Environmental Engineering, Seoul National University) ;
  • Jung, Sung-Jun (Dept. of Civil and Environmental Engineering, Seoul National University) ;
  • Kwon, Oh-Sung (Technology Research Institute, Daelim Industrial Co. Ltd.) ;
  • Kim, Myoung-Mo (Dept. of Civil and Environmental Engineering, Seoul National University)
  • 김석중 (서울대학교 공과대학 건설환경공학부) ;
  • 정성준 (서울대학교 공과대학 건설환경공학부) ;
  • 권오성 (대림산업(주) 기술연구소) ;
  • 김명모 (서울대학교 공과대학 건설환경공학부)
  • Published : 2010.03.25
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Abstract

Load Resistance Factor Design method is used increasingly in geotechnical design world widely and resistance factors for drilled shafts are suggested by AASHTO. However, these resistance factors are determined for intact rock conditions, by comparison most of bedrocks in Korea are weathered condition, so that applying the AASHTO resistance factors is not reasonable. Thus, this study suggests the proper resistance factors for design of drilled shaft in Korea. The 22 cases of pile load test data from 8 sites were chosen and reliability-based approach is used to analyze the data. Reliability analysis was performed by First Order Second Moment Method (FOSM) applying 4 bearing capacity equations. As a result, when the Factor of Safety(FOS) were selected as 3.0, the target reliability index($\beta_c$) were evaluated about 2.01~2.30. Resistance factors and load factors are determined from optimization based on above results. The resistance factors ranged between 0.48 and 0.56 and load factor for dead load and live load are evaluated approximately 1.25 and 1.75 respectively. However, when the target reliability are considered as 3.0, the resistance factors are evaluated as approximately 50% of results when the target reliability index were 2.0.

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