Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Resistance Increasing Factor of Connected-pile Foundation for Transmission Tower in Clay

점토지반에 근입된 송전철탑 연결형 말뚝기초의 저항력증가계수

  • 경두현 (연세대학교 토목환경 공학과) ;
  • 이준환 (연세대학교 토목환경 공학과) ;
  • 백규호 (관동대학교 토목공학과) ;
  • 김대홍 (한국전력공사 전력연구원)
  • Received : 2012.02.20
  • Accepted : 2012.08.07
  • Published : 2012.08.31
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Abstract

Pile foundation for transmission tower constructed in weak ground can cause the damage of the tower due to the different settlement between the foundations. In Japan and USA, connected-pile foundations whose 4 foundations are connected each other by beams were used for transmission tower (TEPCO 1988, IEEE 2001). Resistance increasing factors for connected-pile foundation signify increasing amount of resistance due to the effect of connected-pile material. In this study, we performed model lateral load tests of connected-pile foundations for transmission tower and found the resistance increasing factors for connected-pile foundation. The tests were performed in silty clay, and the resistance increasing factors were founded in various conditions that lateral load directions and height, the stiffness of beams in the connected-pile foundations were changed. The resistance increasing factors from our research were presented as a function of normal lateral loading height and normal stiffness of the connected-pile material. The resistances which were estimated from the resistance increasing factors were similar to measured values.

연약지반에 건설되는 송전철탑 말뚝기초는 부등침하로 인한 철탑구조체의 손상을 유발 할 수 있다. 이에 따라 일본과 미국에서는 철탑을 지지하는 각 기초부를 연결보로 연결한 연결형기초의 사용을 추천하고 있다(TEPCO 1988, IEEE 2001). 연결형 말뚝기초의 저항력증가계수는 연결체의 영향으로 인하여 증가되는 연결형 말뚝기초의 저항력의 증가량을 나타낸다. 본 연구에서는 점토지반에 근입된 송전철탑 연결형말뚝 기초의 모형수평재하시험을 수행하여 연결형 말뚝기초의 저항력증가계수를 도출하였다. 본 시험은 실트질 점토지반에서 수행되었으며, 수평하중의 재하높이와 재하각도, 말뚝기초를 연결하는 연결체의 강성을 변화시켜 다양한 조건상에서의 저항력 증가계수를 도출하였다. 본 연구에서 도출된 저항력 증가계수는 송전철탑의 하중작용높이와 기초를 연결하는 연결체의 강성에 대한 함수로 나타났으며, 도출된 증가계수를 통하여 연결형 말뚝기초의 저항력을 산정한 결과 측정결과와 비교적 일치하는 것으로 나타났다.

Keywords

References

  1. BSI (1986), "British standard code of practice for foundations", BS8004, British Strandard Institution(BSI), London.
  2. Bowles, J. E. (1982), "Foundation Analysis and Design", McGrawHill Book Company, New York.
  3. Fleming, W. G. K., Weltman, A. J., Randolph, M. F. and Elson, W. K. (1992), Piling Engineering 2nd Ed., John Wiley and Sons, New York.
  4. IEEE (2001), "IEEE Guide for Transmission Structure Foundation Design and Testing. (Overturning Moment tests)", IEEE Strandard, pp.691-2001.
  5. ISSMFE (1985), "Axial pile loading test-part 1: static loading", Geotechnical Testing Journal, ASTM, Vol.9, No.2, pp79-89.
  6. Jang, S. H., Kim, H. K., Lee, K. H., Han, K. S., Ham, B. W. and Chung, K. S. (2007), "A study on the transmission tower foundation design and construction Method-A focus of cylindrical foundation", Journal of Korean Institute of Electrical Engineers(KIEE), Vol.56, No.6, pp.1031-1034.
  7. JGS (2002), "Standard for vertical loading test of pile", JGS-1813-2002, Japanese Geotechnial Society.
  8. KEPCO (2011), Design standard for transmission tower foundation, DS-1110.
  9. Kim, J. B., Cho, S. B. (1995), "The design and the full load test results of 765kV tower foundation", Proceedings of Korean Institute of Electrical Engineers(KIEE) fall national conference 1995, pp.447-449.
  10. Kyung, D. H., Lee, J. H., Paik, K. H., Kim, D. H. (2011), "The behavior and resistance of connected-pile roundations for transmission tower from In-situ lateral load tests", Journal of Korean Geotechnical Society(KGS), Vol.27, No.3, pp.27-40.
  11. TEPCO (1988), UHV 基礎設計要項(案), 5.4-5.5