Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Analysis of Characteristics of Connected-pile Foundations for Transmission Tower according to Changes of Load and Connection Beam Conditions in Clay

점토지반에서 하중특성 및 연결보조건에 따른 송전철탑용 연결형 말뚝기초의 특성 분석

  • 경두현 (연세대학교 토목공학과) ;
  • 이준환 (연세대학교 토목공학과) ;
  • 백규호 (관동대학교 토목공학과) ;
  • 김영준 (관동대학교 토목공학과) ;
  • 김대홍 (한국전력공사 전력연구원)
  • Received : 2011.02.18
  • Accepted : 2013.09.23
  • Published : 2013.10.31
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Abstract

The differential settlement between the foundations causes the critical damage on the transmission tower constructed in soft ground. Connected-pile foundation for transmission tower structures is an option to prevent the differential settlement. It consists of main foundations and connection beams that are placed between the individual foundations at each corner of tower. In this study, 24 model pile load tests were conducted at a construction site in jeonlabuk-do to investigate the effects of the connection beams on transmission tower foundation. In model tests, various load conditions and connection beam conditions were considered. As the test results, the displacements of connected-pile foundation differed in accordance with load directions. The settlements of connected-pile foundation decreased with the increased stiffness of connection beams, lateral load capacity decreased in accordance with load height, and the lateral load capacity on the failure criteria was similar regardless of load direction.

부등침하는 연약지반에 시공되는 철탑기초에 있어서 주요한 손상을 야기한다. 송전철탑용 연결형 말뚝기초는 연약지반에서의 송전철탑기초의 부등침하를 방지하기 위한 구조물로서, 주기초체와 주기초체 사이에 위치하여 기초를 연결하는 연결보로 구성된다. 본 연구에서는 송전용 철탑기초에 작용하는 연결보의 영향을 조사하기 위하여, 전라북도에 위치한 건설현장에서 24회의 모형재하시험을 수행하였다. 시험에서는 다양한 하중조건과 연결보 조건이 고려되었으며, 시험결과 수평하중에 의한 연결형 말뚝기초의 발생변위가 철탑에 작용하는 수평하중의 각도에 따라 달라지는 것으로 나타났다. 연결형 기초의 침하는 연결보의 강성이 증가할수록 감소하였으며, 수평지지력은 수평하중이 재하되는 철탑의 높이가 낮을수록 증가하였고, 파괴시점에서의 하중의 크기는 대부분의 경우 하중재하방향에 상관없이 유사한 것으로 나타났다.

Keywords

References

  1. Fellenius, B.H. (1980), "The analysis of results from routine pile load tests", Ground Engineering, Vol.13, No.6, pp.19-36.
  2. 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.
  3. IEEE (2001), "IEEE Guide for Transmission Structure Foundation Design and Testing. (Overturning Moment tests)", IEEE Strandard 691-2001, Institute of Electrical and Electronics Engineers.
  4. Jang, S. H., Kim, H. K., 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 Engineering (KIEE), Vol.56, No.6, pp.1031-1034.
  5. JEC (1979), "Design Standard for Power Transmission Supports", Standard of the Japanese Electrotechnical Committee, JEC-127-1979, Japanese Electrotechnical Committee.
  6. JGS (2002), "Standard for Vertical loading test of pile", JGS-1813- 2002, Japanese Geotechnial Society.
  7. KEPCO (2007), "Outline of 765kV transmission tower foundation and implementation of foundation load test", The Bulletin of Korea earth works, No.7, pp.113-121.
  8. KEPCO (2011), Design standard for tranmission tower foundation, DS-1110, Korea Electronic Power Corporation.
  9. Kim, J. B. and Cho, S. B. (1995), "The design and the full load test results of 765kV tower foundation", Proceeding of Korean Institute of Electrical Engineers (KIEE) fall national conference 1995, pp.447-449.
  10. KGS (2007), "Standard for vertical uplift pile load test", KGS TCF S 3-2007, Korean Geotechnical Society Technical Committee of Foundation.
  11. Kyung D. H., Lee, J. H., Paik, K. H., and Kim, D. H. (2011), "The failure standard to estimate bearing capacity for connected-type foundation of transmission tower and the behavior in clay", Journal of Korean Geotechnical Society, Vol.27, No.3, pp.27-40
  12. Merifield, R.S. and Smith, C.C. (2010), "The Ultimate uplift capacity of multi-plate strip anchors in undrained caly", Computers and Geotechnics, Vol.37, No.4, pp.504-514 https://doi.org/10.1016/j.compgeo.2010.02.004
  13. Rattley, M.J., Richards, D.J., and Lehane, B.M. (2008), "Uplift Performance of Transmission Tower Foundations Embedded in Clay", Journal of Geotechnical and Geoenvironmental Engineering, ASCE, Vol.134, No.4, pp.531-540 https://doi.org/10.1061/(ASCE)1090-0241(2008)134:4(531)
  14. Richards, D.J., White, D.J., and Lehane, B.M. (2010), "Centrifuge modelling of the pushover failure of an electricity transmission tower", Canadian Geotechnical Journal, Vol.47, No.4, pp.413-424. https://doi.org/10.1139/T09-112
  15. TEPCO (1988), "Design guildeline for UHV foundation", Tokyo Electric Power Company, 5.4-5.5.
  16. Vanitha, L., Patra, N.R., and Chandra, S. (2007), "Uplift capacity of pile group anchors", Geotechnical and Geological Engineering, Vol.25, No.3, pp.339-347. https://doi.org/10.1007/s10706-006-9114-3