QUASI-STATIC DEEP PENETRATION IN CLAYS-DISCUSSION

Comments are made on the paper which presents the results of an experimental study of deformations produced by a steady-state penetration of a saturated clay by rigid wedges of various wedge angles. Although the penetration of relatively sharp wedges into clay can be represented quite closely by a Prandtl type cutting mode, it has been found that the wider the wedge angle, the more the results deviate from the predictions based on the cutting theory. Comments are made regarding the explanation for this discrepancy. It is observed that in indentation experiments with metals for blunt wedges and cones, or for materials have a low ratio of Yound's modulus to yield stress, the material displaced by the indenter does not fail in a cutting mode, but is accommodated by an approximately radial expansion of the sorrounding medium. The simplest theoretical model approximating this kind of behavior is the theory of an expanding cylindrical or spherical cavity in an elastic-plastic material. When applicable, the cavity expansion theory offers an additional advantage over the Prandtl type cutting theory of being able to take into account easily and practically any known stress-strain and strength behavior of the soil. Comments are also made on representations of penetration resistances for sharp and blunt wedges.

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  • Accession Number: 00141330
  • Record Type: Publication
  • Report/Paper Numbers: ASCE #11706 Proceeding
  • Files: TRIS
  • Created Date: Oct 26 1976 12:00AM