Applicability of IGM theory Partial Drilled Shaft constructed on Granite Rocks

화강풍화암에 시공된 부분현장타설말뚝의 IGM이론의 적용성

  • Ahn, Tae-Bong (Department of Railroad Construction System, Woosong University)
  • Received : 2013.05.16
  • Accepted : 2013.08.01
  • Published : 2013.10.31


In this study, partial drilled shafts (Bottom Cast-in-place Concrete pile) were applied to the pilot test site to ensure the bearing capacity; we used the skin friction force in the IGM to analyze the feasibility of the application of IGM theory. The soil characteristics were analyzed in cohesive, non-smear, and smooth conditions for the application of the IGM theory via geotechnical investigation and measurement of the disturbance and surface roughness. Static load and load transfer tests were conducted to calculate the allowable bearing capacity and the skin friction force by depth. The skin friction force increased with increase in the depth and standard settlement, showing a very high correlation. In addition, because the unconfined strength ($q_u$), which is the most important parameter in the cohesive IGM, cannot be measured in a weathered granite area, the static load and load transfer test results and the N value were used to obtain $q_u$.


  1. Ministry of land, Transportation, and Maritime Affairs (2008) Road design manual Vol. 5 Bridges, pp. 509-313.
  2. Design criteria of Foundation. (2009) Korean Geotechnical Society.
  3. D.D. Seo (2004) Bearing capacity of cast-in place pile depending on displacement socked in IGM, Hanyang University. Ph.D. Thesis.
  4. H.S. Chang (1996) Vertical bearing capacity and settlement constructed on rocks, Seoul national University, Master thesis pp. 24-72.
  5. J.P. Cater, F.H. Kulhawy (1987) Analysis and Design of Drilled Shaft Foundations Socketed into Rock, Research Report, Geotechnical Engineering Group, Cornell University, Ithaca, New York, January.
  6. B. Ladanyi (1977) Friction and end bearing tests on bedrock for high capacity socket design: Discussion, Canadian. Geotechnical. Journal, 14, pp.153-155.
  7. M. O'Neill, F. Townsend, K. Hanssan, A. Buller P. Chan (1996) Load Transfer for Drilled Shafts in Intermediate Geomaterials, U.S. Department of Transportation, FHWA-RD-95-XXX Draft Report, January.
  8. U.S. Department of Transportation, Federal Highway Administration (1996) Load Transfer for Drilled Shafts in Intermediate Geomaterials, Publication No. FHWA-RD-96-172.
  9. U.S. Department of Transportation, Federal Highway Administration (1999) Drilled Shafts: Construction Procedures and Design Methods, Publication No. FHWA-IF-99-025.
  10. A.S. Vesic (1972) Expansion of Cavities in Infinite Soil Mass, Journal of Soil Mechanics and Foundation. Division, ASCE, Vol.98, SM3, pp. 265-29051.