Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Design of IGM Socketed Drilled Shafts Using Texas Cone Penetrometer Tests

텍사스 콘 관입시험을 이용한 IGM에 근입된 현장타설말뚝의 설계

  • Nam, Moon-S. (Department of Geotechnical Engrg., Highway & Transportation Technology Institute, Korea Highway Corporation)
  • 남문석 (한국도로공사 도로교통기술원)
  • Published : 2006.10.31
Download PDF
⟨ Previous Next ⟩

Abstract

Modern methods for designing IGM(Intermediate Geomaterial) socketed drilled shafts require knowledge of the compressive strength and modulus of the IGM. However, the weathered IGMs at many sites prohibit the recovery of samples of sufficient length and integrity to test cores in either unconfined or triaxial compression tests. Since rational design procedures usually require values of compressive strength, surrogate methods must be employed to estimate the compressive strength of the IGM. A surrogate method considered in this study was Texas cone penetrometer tests which were performed at several sites in North Central Texas. Correlations of Texas cone penetrometer tests and compressive strengths of cores from these formations are provided in the paper. In order to develop the relationships between Texas cone penetrations and side and base resistance of IGM socketed drilled shafts, three filed load tests were conducted in the same sites. Based on the field study and literature reviews, a design method for IGM socketed drilled shafts using Texas cone penetration test was proposed.

IGM(Intermediate Geomaterial)에 근입된 현장타설말뚝의 설계를 수행하기 위해서는 대상 지반의 강도특성을 알아야 하고, 이를 위해 IGM에 대한 일축이나 삼축 등의 압축강도시험을 수행한다. 그러나, 설계 대상의 IGM지반이 풍화가 된 경우에는 압축강도시험을 통한 강도특성 파악이 힘들다. 이러한 경우에는 압축강도시험을 대체하여 IGM지반의 강도 특성을 파악할 수 있는 방법들이 필요로 한다. 본 연구에서는 현재 텍사스주 도로국(Texas Department of Transportation)에서 말뚝기초의 설계인자로서 사용 중인 텍사스 콘 관입시험(Texas Cone Penetrometer Test)을 이용하여 IGM지반의 역학특성을 파악하였다. 그리고 미국의 텍사스주 지역에 분포하는 IGM지반인 셰일(Clay Shale)과 석회암(Limestone)을 대상으로 시험현장을 선택하였고 말뚝재하시험과 텍사스 콘 관입시험을 수행하였다. 본 연구결과를 바탕으로 텍사스 콘 관입시험과 IGM 근입 현장타설말뚝의 주면마찰력과 선단지지력과의 상관관계를 제시하였다.

Keywords

References

  1. American Society of Testing and Materials (2000), 'Annual Book of ASTM Standards', Vol. 4.02, ASTM, West Conshohocken, Philadelphia
  2. Aurora, R. P., and Reese, L. C (1976), 'Behavior of Axially Loaded Drilled Shafts in Clay-Shales', Research Report 176-4, Center for Highway Research, The University of Texas at Austin, Austin, Texas
  3. Hassan, K. M., and O'Neill, M. W. (1997). 'Side Load Transfer Mechanisms in Drilled Shafts in Soft Argillaceous Rock', Journal of Geotechnical and Geoenvironmental Engineering, Vol.123, No.2, ASCE, pp.145-152 https://doi.org/10.1061/(ASCE)1090-0241(1997)123:2(145)
  4. Hassan, K. M. (1994), 'Analysis and Design of Drilled Shafts Socketed into Soft Rock', Ph. D. Thesis, Department of Civil & Environmental Engineering, University of Houston, Houston, Texas
  5. Kulhawy, F. H., and Phoon, K-K (1993), 'Drilled Shaft Side Resistance in Clay Soil to Rock', Design and Performance of Deep Foundations, GSP No. 38, Ed. by P. P. Nelson, T. D. Smith and E. C Clukey, ASCE, October, pp.172-183
  6. McVay, M. C., Townsend, F. C., and Williams, R. C. (1992), 'Design of Socketed Drilled Shaft in Limestone', Journal of Geotechnical Engineering, Vol.118, No.10, ASCE, pp.1626-1637 https://doi.org/10.1061/(ASCE)0733-9410(1992)118:10(1626)
  7. McVay, M., Ellis, Kim, M., Villegas, J., Kim, S-H, and Lee, S. M. (2003), 'Static and Dynamic Field Testing of Drilled Shafts: Suggested Guidelines on Their Use and for FOOT Structures', Report No. WPI No. BC354-08, FDOT, Department of Civil and Costal Engineering, University of Florida
  8. Nam, M. S. (2004), 'Improved Design for Drilled Shafts in Rock', Ph. D. Dissertation, Department of Civil & Environmental Engineering, University of Houston, Houston, Texas
  9. O'Neill, M. W., Reese, L. C., Bames, R, Wang, S. T., Morvant, M., and Ochoa, M. (1992), 'Effects of Stratigraphic and Construction Details on the Load Transfer Behavior of Drrilled Shafts', Transportation Research Record, No.1336, pp.50-56
  10. O'Neill, M. W., and Reese, L. C. (1999), 'Drilled Shafts: Construction Procedures and Design Methods', FHWA Publication No. FHWA IF 99 025. Department of Transportation, Federal Highway Administration, Office of Implementation, McLean, VA
  11. PLAXIS-Finite Element Code for Soil and Rock Analyses Program, Version 7.2 (1998), Plaxis BV. AN Delft, The Netherlands
  12. Rowe, P. K., and Armitage, H. H. (1987), 'A Design Method for Drilled Piers in Weak Rock', Canadian Geotechnical Journal, Vol.24, pp.126-142 https://doi.org/10.1139/t87-011
  13. Seikh, S., O'Neill, M. W., and Kapasi, K. J. (1985), 'Behavior of 45$^{\circ}$ Underream Footing in Eagle Ford Shale', Research Report No. 85-12, University of Houston, December, 129 pp, Houston, Texas
  14. Sellards, E. H., Adkins, W. S., and Plummer, F. B. (1932), 'The Geology of Texas-Volume I, Stratigraphy', The University of Texas Bulletin No. 3232, Bureau of Economic Geology, Austin, Texas
  15. Texas Department of Transportation (1993), 'Standard Specifications for Construction of Highways, Streets and Bridges', Texas Department of Transportation, Austin, Texas
  16. Texas Department of Transportation (1995), Manual of Testing Procedures, 100-E Series
  17. Texas Department of Transportation (2000). 'Geotechnical Manual (On Line Version)', Texas Department of Transportation, Bridge Division, Austin, Texas