KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
권호 표지
DOI QR코드

DOI QR Code

Buckling Loads of Piles with Allowance for Self-Weight

자중효과를 고려한 말뚝의 좌굴하중

  • 이준규 (서울시립대학교 토목공학과) ;
  • 이광우 (연세대학교 공학연구원) ;
  • 전영진 (강원대학교 산업기술연구소) ;
  • 권오일 (벽산엔지니어링 플랜트사업본부) ;
  • 최용혁 (서울시설공단 도로시설처) ;
  • 최정식 (경기도청 건설본부 북부도로과)
  • Received : 2022.11.29
  • Accepted : 2023.01.24
  • Published : 2023.04.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper presents the buckling behavior of a pile considering its self-weight. The differential equation and boundary conditions governing the buckling of partially embedded piles in nonhomogeneous soils are derived. The buckling load and mode shape of the pile are numerically computed by the Runge-Kutta method combined with the Regula-Falsi algorithm. The obtained numerical solutions for bucking loads agree well with the results available from the literature. Numerical examples are given to analyze the buckling load and mode shape of the piles as affected by the self-weight, embedment ratio, slenderness ratio and boundary condition of the pile as well as the aspect ratio and rigidity ratio of the subgrade reaction. It is found that the self-weight of the pile leads to the reduction of the buckling load, indicating that neglecting the effect of self-weight may overestimate the buckling load of partially embedded piles.

이 논문은 말뚝체의 자중을 고려한 말뚝의 좌굴거동에 관한 연구이다. 비균질 지반에 설치된 부분매립 말뚝의 좌굴을 지배하는 미분방정식과 경계조건을 유도하였다. Runge-Kutta법과 Regula-Falsi법을 결합한 수치해석법을 적용하여 말뚝의 좌굴하중과 좌굴형을 산정하였다. 계산된 좌굴하중의 수치해와 문헌값은 잘 일치하였고, 수치예를 통해 말뚝의 자중, 매립비, 세장비, 경계조건 및 지반의 반력형상비, 지반강성비가 말뚝의 좌굴특성에 미치는 영향을 분석하였다. 분석결과, 말뚝의 자중은 말뚝의 좌굴하중을 감소시켰으며 이러한 자중효과의 무시는 부분매립 말뚝의 좌굴하중을 과대평가할 수 있음을 확인하였다.

Keywords

Acknowledgement

이 논문은 2022년도 서울시립대학교 연구년교수 연구비에 의하여 연구되었습니다. 제1저자는 노스캐롤라이나 대학교 교환교수로 초청해주신 John L. Daniels 교수님께 감사드립니다.

References

  1. AASHTO (2020). LRFD bridge design specifications, 9th edition, American Association of State Highway and Transportation Officials, USA.
  2. Bjerrum, L. (1957). "Norwegian experience with steel piles to rock." Geotechnique, Vol. 7, No. 2, pp. 73-96. https://doi.org/10.1680/geot.1957.7.2.73
  3. Chen, Y. H., Chen, L., Wang, X. and Chen, G. (2015). "Critical buckling load calculation of piles based on cusp catastrophe theory." Marine Geoscience and Geotechnology, Vol. 33, No. 3, pp. 222-228. https://doi.org/10.1080/1064119X.2013.836259
  4. Dash, S. R., Bhattacharya, S. and Blakeborough, A. (2010). "Bending-buckling interaction as a failure mechanism of piles in liquefiable soils." Soil Dynamics and Earthquake Engineering, Vol. 30, No. 1-2, pp. 32-39. https://doi.org/10.1016/j.soildyn.2009.08.002
  5. Gabr, M. A., Wang, J. J. and Zhao, M. (1997). "Buckling of piles with general power distribution of lateral subgrade reaction." Journal of Geotechnical and Geoenvironmental Engineering, Vol. 123, No. 2, pp. 123-130. https://doi.org/10.1061/(ASCE)1090-0241(1997)123:2(123)
  6. Gere, J. M. and Timoshenko, S. P. (1997). Mechanics of materials, PWS Publishing Company, MA, USA.
  7. Heel is, M. E ., Pavl ovic, M. N . and West, R . P. ( 2004). "The analytical prediction of the buckling loads of fully and partially embedded piles." Geotechnique, Vol. 54, No. 6, pp. 363-373. https://doi.org/10.1680/geot.2004.54.6.363
  8. Korean G eotechnical Society (KGS) (2015). Korean foundation engineering code, Korean Geotechnical Society (in Korean).
  9. Lee, J. K. (2022). "Lateral free vibration of rectangular barrettes subjected to vertical loading." Marine Georesources and Geotechnology, Vol. 140, No. 8, pp. 1-10. https://doi.org/10.1080/1064119X.2021.1948936
  10. Lee, J. K., Jeong, S. S. and Kim, Y. H. (2018). "Buckling of tapered friction piles in inhomogeneous soil." Computers and Geotechnics, Vol. 97, pp. 1-6. https://doi.org/10.1016/j.compgeo.2017.12.012
  11. Lee, J. K. and Lee, B. K. (2020). "Buckling lengths of heavy column with various end conditions." Engineering Soild Mechanics, Vol. 8, pp. 163-168. https://doi.org/10.5267/j.esm.2019.9.005
  12. Liang, F., Zhang, H. and Huang, M. (2015). "Extreme scour effects of the buckling of bridge piles considering the stress history of soft clay." Natural Hazards, Vol. 77, No. 2, pp. 1143-1159. https://doi.org/10.1007/s11069-015-1647-4
  13. Prakash, S. (1987). "Buckling loads of fully embedded vertical piles." Computers and Geotechnics, Vol. 4, No. 2, pp. 61-83. https://doi.org/10.1016/0266-352X(87)90011-5
  14. Prakash, S. and Sharma, H. D. (1990). Pile foundations in engineering practice, John Wiley and Sons, New York, USA.
  15. Rowe, R. K. and Booker, J. R. (1981). "The behavior of footings resting on a non-homogeneous soil mass with a crust. Part I. Strip footings." Canadian Geotechnical Journal, Vol. 18, No. 2, pp. 250-264. https://doi.org/10.1139/t81-028
  16. Vogt, N., Vogt, S. and Kellner, C. (2009). "Buckling of slender piles in soft soils." Bautechnik, Vol. 86, No. S1, pp. 98-112. https://doi.org/10.1002/bate.200910046
  17. West, R. P., Heelis, M. E., Pavlovic, M. N. and Wylie, G. B. (1997). "The stability of end-bearing piles in a non-homogeneous elastic foundation." International Journal for Numerical and Analytical Methods in Geomechanics, Vol. 21, No. 12, pp. 845-861. https://doi.org/10.1002/(SICI)1096-9853(199712)21:12<845::AID-NAG905>3.0.CO;2-7
  18. Zdravkovic, L., Potts, M. and Jackson, C. (2003). "Numerical study of the effect of preloading on undrained bearing capacity." International Journal of Geomechanics, Vol. 2, No. 1, pp. 1-10. https://doi.org/10.1061/(ASCE)1532-3641(2003)3:1(1)