NUMERICAL DESIGN-ANALYSIS FOR PILES IN SANDS

The finite element method has been used to study the behavior of foundation piles in cohesive and granular soils, assuming several constitutive equations for the soil. Experimental results given in the literature have been analyzed introducing a hyperbolic stress-strain curve for cohesive soil in the finite element model. The numerical results agree well with the experimental data both for settlements and bearing capacity values when the elastic modulus distribution in the soil is close to that determined by in-situ tests (K=600). The distribution of vertical stresses in the piles for increasing values of the applied load has also been obtained showing that only a small fraction of the applied load is transmitted to the pile base even for load values close to the ultimate bearing capacity of the pile. The failure mechanism of the soil is shown; failure in the soil starts near the head and the base of the pile and extends gradually along the pile as the applied load increases. The discussers comment on the use of joint elements at the pile-soil interface, and the inclusion of these special elements in the finite element scheme. Comments are made on the determination of mechanical parameters of the interface elements for bored piles in cohesive soils, the comparison of the finite element analysis with experimental load settlement curves, and the presence of tensile stresses in the soil around the pile. The discussers emphasize the importance of using the elastic modulus distribution in the analysis, preferably obtained on the basis of in-situ tests.

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  • Accession Number: 00099101
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #11398 Proceeding
  • Files: TRIS
  • Created Date: Oct 18 1975 12:00AM