ANALYTICAL MODELING OF THE UPLIFT BEHAVIOR OF DRILLED SHAFT FOUNDATIONS

The studies conducted and presented in this report are designed to establish an approach for applying the finite element method to predict the behavior of straight-sided drilled shafts subjected to uplift loads. The techniques presented use nonlinear, stress-dependent impirical models for the soil, shaft and soil-shaft interface properties which can simulate construction sequences employed in the field. Where possible, checks are made to test the validity and accuracy of this approach by comparing the finite element results with solutions provided from elastic theory or from the results of several instrumented, large scale model uplift load tests. In these cases, good to excellent comparisons were found. Based upon these results, a number of generalized analyses are performed to evaluate the relative effects that construction procedures, shaft geometry, material properties and in-situ stress conditions have in controling shaft behavior. These studies show that straight-sided drilled shafts fail along or near to the soil shaft interface and that the pattern is essentially independent of construction operations, shaft size and soil conditions. Accordingly, it is shown that a simple limit equilibrium approach can provide good estimates of the shaft capacity determined from a finite element analysis. A simple and accurate modified elasticity procedure is also presented to estimate values for butt displacement at shaft yield. /Author/

  • Supplemental Notes:
    • Performed under contract to Niagara Mohawk Power Corporation.
  • Corporate Authors:

    Cornell University

    School of Civil and Environmental Engineering
    Ithaca, NY  United States  14853
  • Authors:
    • Withiam, J L
    • Kulhawy, F H
  • Publication Date: 1978-3

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 343 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00188189
  • Record Type: Publication
  • Source Agency: Cornell University
  • Report/Paper Numbers: Geotech Eng Rpt 78-1Final Rpt.
  • Contract Numbers: B-49(3)
  • Files: TRIS
  • Created Date: Mar 28 1979 12:00AM