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An application of wave equation analysis program to pile dynamic formulae

  • Tokhi, H. (School of Civil, Environmental and Chemical Engineering, RMIT University) ;
  • Ren, G. (School of Civil, Environmental and Chemical Engineering, RMIT University) ;
  • Li, J. (School of Civil, Environmental and Chemical Engineering, RMIT University)
  • 투고 : 2014.04.15
  • 심사 : 2015.05.06
  • 발행 : 2015.09.25

초록

Wave equation analysis programs (WEAP) such as GRLWEAP and TNOWave were primarily developed for pre-driving analysis. They can also be used for post-driving measurement applications with some refinements. In the case of pre-driving analysis, the programs are used for the purpose of selecting the right equipment for a given ground condition and controlling stresses during pile driving processes. Recently, the program is increasingly used for the post-driving measurement application, where an assessment based on a variety of input parameters such as hammer, driving system and dynamic behaviour of soil is carried out. The process of this type of analysis is quite simple and it is performed by matching accurately known parameters, such as from CAPWAP analysis, to the parameters used in GRLWEAP analysis. The parameters that are refined in the typical analysis are pile stresses, hammer energy, capacity, damping and quakes. Matching of these known quantities by adjusting hammer, cushion and soil parameters in the wave equation program results in blow counts or sets and stresses for other hammer energies and capacities and cushion configuration. The result of this analysis is output on a Bearing Graph that establishes a relationship between ultimate capacity and net set per blow. A further application of this refinement method can be applied to the assessment of dynamic formulae, which are extensively used in pile capacity calculation during pile driving process. In this paper, WEAP analysis is carried out to establish the relationship between the ultimate capacities and sets using the various parameters and using this relationship to recalibrate the dynamic formula. The results of this analysis presented show that some of the shortcoming of the dynamic formula can be overcome and the results can be improved by the introduction of a correction factor.

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참고문헌

  1. AbdelSalam, S., Sritharan, S. and Suleiman, M.T. (2009), "Current design and construction practices of bridge pile foundations", Proceedings of International Foundation Congress and Equipment Expo 2009, Orlando, FL, USA, March, pp. 458-465.
  2. Broms, B. and Lim, P.C. (1988), "A simple pile driving formula based on stress-wave measurements", Proceedings of the 3rd International Conference on the Application of Stress-Save Theory to Piles, Vancouvar, Canada, MONTH.
  3. Chellis, R.D. (1961), Pile Foundations, McGraw-Hill.
  4. Fleming, K., Weltman, A., Randolph, M. and Elson, K. (2008), Piling Engineering, (3rd Edition), Taylor & Francis.
  5. Hiley, A. (1925), "Rational pile-driving formula and its application in piling practice explained", Engineering, 119(3100), 657-658.
  6. Hussein, M.H. (2004), "A brief history of the application of stress wave theory to piles: Current practices and future trends in deep foundation", Proceedings of Current Practices and Future Trends in Deep Foundations, Los Angeles, CA, USA, July.
  7. Isaac, D.V. (1931), "Reinforced concrete pile formulae", Transactions, Institute of Engineers, Australia, 12(370), 305-324.
  8. Lowery, L.L. Jr., Hirsch, T.J., Edwards, T.C., Coyle, H.M. and Samson, C.H. Jr. (1969), "Pile driving analysis - State of the art", Texas: Texas Transportation Institute.
  9. Paikowsky, S., Regan, J. and McDonnell, J. (1994), "A simplified field method for capacity evaluation of driven piles", FHWA.
  10. Pile Dynamics Inc. (PDI) (2005), GRLWEAP Wave Equation Analysis of Pile Driving: Procedures and Models Manual, Cleveland, OH, USA.
  11. Smith, E.A.L. (1950), "Pile driving impact", Proceedings of the Industrial Computation Seminar, New York, NY, USA, September.
  12. Smith, E.A.L. (1960), "Pile driving analyses by the wave equation", J. Soil Mech. Found. Div., ASCE., 86, 35-61.
  13. Timoshenko, S.P. and Goodier, J.N. (1951), Theory of Elasticity, (2nd Ed.), McGRaw-Hill Book Company, New York, NY, USA.
  14. Tokhi, H., Ren, G. and Xie, Y.M. (2011), "A new application of radar in improving pile dynamic formula used in the quality control of pile foundation", Australian Geomechanic Society (AGS), 46(4), 35-49.
  15. Whitaker, T. (1970), The Design of Pile Foundation, (1st Ed.).