ACOUSTIC EMISSION BEHAVIOR OF COHESIVE SOILS

In the paper the difference observed in the behavior of clay and sand in acoustic emission was attributed to increase in stress due to particle orientation. If it is accepted that the greater the friction mobilization, the greater the acoustic emission, it is difficult to conceive why the emission decreases in the case of the clay sample with continued deformation while the opposite is the case with sands. It is only logical to conclude that near failure more contacts are broden than formed and the emission should increase, unless friction decreases as in the case of residual shear. Repeated shear tests or ring shear tests with large strains where failure takes place on ariented surfaces are suggested to ascertain the relationship between the mobilization of shear stresses (on prolonged shearing) the material as a result of which the structural damage is counterbalanced by the strengthening effect of closing the pores of the structure as in the soft rocks. It is felt that this behavior in cohesive soils may be due to the acoustic emission's being due to the structure's breakdown during shearing, i.e. the dilatancy component is more truly reflected in the emission than the sliding component. (The sands tested may have been strongly dilatant at failure due to the low confining pressure.) If the volume changes during shear are more reflected in acoustic emission than sliding, then the technique presented in the paper is well adapted for the study of failure problems in collapsing sands and quick clays.

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  • Accession Number: 00178882
  • Record Type: Publication
  • Report/Paper Numbers: ASCE 13838 Proceeding
  • Files: TRIS
  • Created Date: Sep 27 1978 12:00AM