Journal of the Korean Geosynthetics Society (한국지반신소재학회논문집)

Korean Geosynthetics Society (한국지반신소재학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of Lateral Subgrade Reaction Coefficient Considering Empirical Equation and Horizontal Behavior Range of Large Diameter Drilled Shaft

경험식을 통한 대구경 현장타설말뚝에 대한 수평지반반력계수와 수평거동 영향범위의 평가

  • Yang, Woo-Yeol (Dept. of Civil Engineering, Daejin University) ;
  • Hwang, Tae-Hyun (Dept. of Civil Engineering, Daejin University) ;
  • Kim, Bum-Joo (Department of Civil and Environmental Engineering, Dongguk University) ;
  • Park, Seong-Bak (Dept. of Civil Engineering, Daejin University) ;
  • Lee, Kang-Il (Dept. of Civil Engineering, Daejin University)
  • Received : 2020.03.04
  • Accepted : 2020.06.01
  • Published : 2020.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The lateral bearing characteristics of large diameter drilled shaft depend greatly on the stiffness of the pile, horizontal subgrade reaction of adjacent ground. In particular, the empirical evaluation results of the horizontal subgrade reaction coefficient which are widely used in pile design are very important factors in evaluating the lateral bearing capacity of drilled shaft because the difference in bearing capacity depends on the estimated result. Nevertheless, the evaluation of the horizontal subgrade reaction coefficient on the large diameter drilled shaft is insufficient. In addition, although the range of influence and the location of the maximum moment which is the weaken zone on the pile may be correlated and relationship of these are major consideration in determining the reinforced zone of drilled shaft, the previous studies have not been evaluated it. In this study, the field test and nonlinear analysis of large diameter drilled shaft were performed to evaluate the horizontal subgrade reaction coefficient and to investigate the relationship between the influence range 1/β of the pile and the location of the maximum moment zm. In the result, the lateral bearing capacity of drilled shaft showed a difference in results by about 190% according to the empirical equation on the horizontal subgrade reaction coefficient. And the relationship between the influence range of the pile and the location of the maximum moment was evaluated as a linear relationship depending on the soil density.

대구경 현장타설말뚝의 수평지지 특성은 말뚝의 강성, 인접지반의 수평지반반력에 따라 크게 좌우된다. 특히 말뚝설계 시 많이 활용되는 경험적인 수평지반반력계수는 그 결과의 값에 따라서 지지력의 차이가 크므로 수평지지력을 평가하는 데 매우 중요한 요소임에도 불구하고 대구경 현장타설말뚝에 대한 지반반력계수의 평가가 미흡한 실정이다. 또한, 말뚝의 취약부인 수평하중에 대한 영향범위와 최대 모멘트의 발생위치는 서로 상관관계가 있을 수 있고, 수평하중에 대한 말뚝의 보강영역을 판단하는데 주요 고려사항임에도 기존 연구에서는 이 관계에 대해 평가되지 않았다. 이에 본 연구는 대구경 현장타설말뚝의 수평지반반력계수를 평가하고, 말뚝의 영향범위(1/β)와 최대 모멘트의 발생위치(zm)의 관계를 조사하고자 대구경 현장타설말뚝에 대한 현장시험과 비선형 해석을 수행하였다. 연구결과, 대구경 현장타설말뚝의 수평지지력은 경험식을 통한 산정결과에 따라 최대 190%정도 차이를 보였다. 또한, 말뚝의 수평거동에 대한 영향범위와 최대 모멘트의 발생위치의 관계는 지반조건에 따라 선형적 관계인 것으로 평가되었다.

Keywords

References

  1. Ahn, S. Y., Jeong, S. S. and Kim, J. Y. (2011), "Proposal of a New Design Method of the Pile-Bent Structure Considering Plastic Hinge", Journal of Korean Geotechnical Society, KGS, Vol.27, No.2, pp.91-101. https://doi.org/10.7843/kgs.2011.27.2.091
  2. ASTM D 3966-7 (2011), "Standard Test Methods for Deep Foundations Under Lateral Load", ASTM Internationl, West Conshohocken, PA 19428-2959, United States.
  3. Bowles, J. E. (1988), "Foundation Analysis and Design: 4th Edition", McGraw-Hill, New-York, pp.623-637.
  4. Bowles, J. E. (1997), "Foundation Analysis and Design: 5th Edition", McGraw-Hill, New-York, pp.501-506.
  5. Broms, B. (1964), "The Lateral Resistance of Piles in Cohesionless Soils", Journal of Soil Mechanics and Foundations Division, ASCE, Vol.90, SM2, pp.123-156. https://doi.org/10.1061/JSFEAQ.0000614
  6. Chen, W. W.(1978), "Discussion: Lateral Load Piles: Program Documentation", Journal of Geotechnical Engineering Division, ASCE, Vol.103, GT1, pp.161-162. https://doi.org/10.1061/AJGEB6.0000568
  7. Choi, I. G. and Park, Y. M. (2016), "Geotechnical Engineering for Field Practice", Goomibook, Korea, pp.489-494.
  8. Das, B. M. (2011), "Principle of Foundation Engineering-Seven Edition", CENGAGE Learning, USA, pp.64-126.
  9. Davisson, M. T. and Prakash, S. (1963), "A Review of Soil Pile Behavior", Highway Research Record, No.39, pp.25-48.
  10. FHWA (1999), "DRILLED SHAFTS: Construction Procedures and Design Methods", Publication No.FHWA-IF-99-025, FHWA, pp.386-420.
  11. FHWA (2010), "Drilled Shafts: Construction Procedures and LRFD Design Methods", Publication No. FHWA-NHI-10-016, FHWA, pp.12‑1-12‑62.
  12. Hong, W. P. and Yun, J. M. (2013), "The Lateral Load Capacity of Bored-Precast Pile Depending on Injecting Ratio of Cement Milk in Sand", Journal of Korean Geosynthetics Society, KGSS, Vol.12, No.4, pp.99-107. https://doi.org/10.12814/jkgss.2013.12.4.099
  13. Honjo, Y., Zaika, Y. and Pokharel, G. (2005), "Estimation of Subgrade Reaction Coefficient for Horizontally Loaded Piles by Statistical Analyses", Soils and Foundations, Japanese Geotechnical Society, Vol.45, No.3, pp.51-70. https://doi.org/10.3208/sandf.45.3_51
  14. Hukuoka, M. (1966), "Damage to civil engineering structures", Soils and Foundations, Japanese Geotechnical Society, Vol.6, No.2, pp.125-145.
  15. Jeong S. S. and Kim, J. Y. (2013), "Analysis of Optimized Column-pile Length Ratio for Supplementing Virtual Fixed Point Design of Bent Pile Structures", Journal of the Korean Society of Civil Engineers, KSCE, Vol.33, No.5, pp.1915-1933. https://doi.org/10.12652/Ksce.2013.33.5.1915
  16. Kang, B. G., Park, M. C., Lee, S. H., Jang, K. S., Koo, J. G. and Park, K. G. (2016) "A Study on Evaluation of Modulus of Horizontal Subgrade Reaction through Field Test and Numerical Analysis", Journal of the Korean Geo- Environmental Society, KGES, Vol.17, No.4, pp.5-15.
  17. KGS (2015), "Design code of Structure Foundation", CIR, Seoul, pp.343-351.
  18. Kim, K. W., Park, J. J. and Kim, J. W. (2016), "Analysis of Lateral Behavior of Steel Pile embedded in Basalt", Journal of Korean Geosynthetics Society, KGSS, Vol.15, No.1, pp.1-10. https://doi.org/10.12814/jkgss.2016.15.1.001
  19. Kim, S. K. (2004), "Soil Mechanic: Theory and Application", CHEONG MOON GAK, Gyenggi, pp.24-36.
  20. Lee, S., Lee, J. D. and Kim, T. H. (2001), "Evaluation of coefficients of subgrade reaction by laterally loaded pile", Journal of Korean So Society of Civil Engineers, KSCE, Vol.21, No.4-C, pp.349-357.
  21. Nadilla, S. and Prakaso, W. A. (2019), "Pile lateral subgrade reaction modulus for Jakarta", MATEC Web of Conferences, ConCERN-2 2018 (https://doi.org/10.1051/matecconf/201927002002).
  22. NAVFAC (1986), "Foundations and Earth Structure", NAVFAC Design Manual 7.2, Naval Facilities Engineering Command, Alexandria, VA., pp.7.2-177-7.2-234.
  23. Palmer, L. A. and Thomopson, J. B. (1948), "The Earth Pressure and Deflection Along the Embedded Length of Piles Subjected to Lateral Thrust" Proceedings Second International Conference of Soil Mechanics and Foundation Engineering, Rotterdam, Holland, Vol.5, pp.156-161.
  24. Prakash, S. and Sharma, H. D. (1990), "Pile Foundations in Engineering Practice", John Wiley & Sons, New-York, pp.322-388.
  25. Ryu, S. Y., Kwal, N. K., Park, M. C., Jeong, S. G. and Lee, S. (2012), "Estimation of Coefficient of Horizontal Subgrade Reaction by the Inverse Analysis on the Lateral Load Test Results", Journal of Korean Geo-Environmental Society, KGES, Vol.13, No.8, pp.15-24.
  26. Vesic, A. B. (1961), "Bending of beams resting on isotropic elastic solid", Journal of the Engineering Mechanics Division, ASCE, Vol.87, No.2, pp.35-54. https://doi.org/10.1061/JMCEA3.0000212

Cited by

  1. 비선형해석을 이용한 케이싱 보강조건에 따른 대구경 현장타설말뚝의 수평거동특성 vol.19, pp.3, 2020, https://doi.org/10.12814/jkgss.2020.19.3.023