Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지

Experimental Study on the Load Sharing Ratio of G개up Pile

무리말뚝의 하중분담률에 관한 실험적 연구

  • Published : 2005.07.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, the large scale model tests were executed to estimate the Load Sharing Ratio (LSR) of raft in a piled footing under various conditions. The conditions such as the subsoil type, pile length, pile spacing, away type and pile installation method etc. were varied in the pile loading tests about the free-standing group piles and a piled footing. As a result of this study, it was found that there was no difference in the load-settlement curves, resulting from the pile installation method and subsoil type. The piles supported most of the external load until a yielding load of the piled footing, but the raft supported a considerable load after a yielding load. As the relative density of sands increased, the LSR decreased. As the pile spacing was wider and the pile length increased, there was a tendancy for the LSR to increase. But it was also found that the LSR was not affected by the pile installation method and the subsoil type.

본 연구에서는 말뚝지지 전면기초에 대한 대규모 모형실험을 실시하여 여러 가지 조건에 따른 하중분담률을 측정하였다. 모형실험은 동일한 조건하에서 비접촉 무리말뚝과 말뚝지지 전면기초 두가지 상태로 실시되었고, 지반의 상대밀도와 종류, 말뚝길이, 간격, 배열상태와 말뚝관입방법 등의 조건들을 변화시켜 실험을 실시하였다. 모형실험 결과, 말뚝관입방법과 지반 종류에 따른 하중-침하 곡선은 큰 차이가 없는 것으로 나타났다 재하하중이 작은 경우에는 대부분의 하중을 말뚝들이 부담하지만, 하중이 커지면 래프트도 상당한 하중을 분담하는 것으로 나타났다. 모래지반의 상대밀도가 높을수록 말뚝지지 전면기초의 하중분담률은 감소하는 경향을 나타내며, 말뚝간격이 넓어지고, 말뚝길이가 길어질수록 하중분담률은 증가하는 경향을 나타냈다. 그러나 말뚝관입방법과 하부 지반의 종류는 말뚝지지 전면기초의 하중분담률에 큰 영향을 주지 않는 것으로 평가되었다.

Keywords

References

  1. 대한토목학회 (2001), 도로교 설계기준 해설(하부구조편), 건설정보사
  2. Chow, Y. K. and Teh, C. I. (1991). Pile-cap-pile-group interaction in nonhomogenous soil. ASCE, 117(11), 1655-1668
  3. Cooke, R. W., Bryden-Smith, D. W., Gooch, M. N., and Sillett, D. F. (1981), Some observations of the foundation loading and settlement of a multi-storey building on a piled raft foundation in London Clay. Proc. Instn Civ. Engrs, Part 1, 70, 433-460
  4. Hain, S. J. and LEE, I. K. (1978), The analysis of flexible raft-piles systems. Geotechnique, 28(1), 65-83 https://doi.org/10.1680/geot.1978.28.1.65
  5. Horikoshi, K. and Randolph, M. F. (1996), Centrifuge modeling of piled raft foundations on clay. Geotechnique, 46(4), 741-752 https://doi.org/10.1680/geot.1996.46.4.741
  6. Katzenbach, R., Arslan, U., and Moormann, C. (2000), Piled raft foundation projects in Germany (Hemsley, J. A., Ed.). London: Thomas Telford
  7. Kishida, H., & Meyerhof, G. G. (1965), Bearing capacity of pile groups under eccentric loads in sand. 6th ICSMFE, 2(4), Montreal, 270-274
  8. Kuwabara, F. (1989), An elastic analysis for piled raft foundations in a homogeneous soil, Soils and Foundations, 22(1), 82-92
  9. Ottaviani, M. (1975), Three-dimensional finite element analysis of vertically loaded pile groups. Geotechnique, 25(2), 15-174
  10. Poulos, H. G. (1968), Analysis of the settlement of pile groups. Geotechnique, 20(18), 449-471
  11. Poulos, H. G. (1994), An approximate numerical analysis of pile-raft interaction. International Journal for Numerical and Analytical Methods in Geomechanics, 18(20), 73-92 https://doi.org/10.1002/nag.1610180202
  12. Yamashita, K., Kakurai, M., and Matsuyama, K. (1989), Settlement analysis of large-diameter bored pile groups. 12th ICSMFE, 2(10), Rio De Janeiro, 13-18
  13. Yamashita, K., Kakurai, M., Yamada, T., and Kuwabara, F. (1993), Settlement behavior of a five-stroy building on a piled raft foundation. Proceeding 2nd International Geotechnical Seminar on Deep Foundations on Bored and Auger Piles, 3(11), Rotterdam, 351-356
  14. Vesic, A. S. (1969), Experiments with instrumented pile groups in sand. Performance of Deep Foundations, ASTM STP 444, 177-222