PHYSICAL ISOMORPHISM IN THE MECHANICAL BEHAVIOUR OF SOILS

The validity of Buckingham's theorem for a group of soils indicates that the behaviour complies with the condition of physical similitude. Buckingham's dimensionless arguments can be generalized using the conception of dimensionless "criterial" functions, of stress-strain diagram for example; behaviour in harmony with these functions is called physically isomorphous behaviour. By analysing some experimental findings, the author shows that typical for isomorphous behaviour are logarithmic curves (e.g., curve of compression or primary creep) and linear Mohr's envelopes. Two deformation mechanisms are discriminated, that of sliding deformation and that of cataclastic deformation. Only the domination of the first one produces physical isomorphism. Microrheological analysis shows, in a rather qualitative way, that physical isomorphism results from the monotonous strain, stress, and time hardening of the structure of the soils in question. Such structural changes are typical for soft to medium clays and loose sands and for many soils in the range of high pressures. These soils manifest, consequently, physically isomorphous behaviour. The importance of the principle of physical isomorphism is illustrated by its application to creep (Saito-Uezawa relation), to primary consolidation of specimens with varying drainage paths, and to the interpretation of the ratio of compression index to secondary compression index.

• Corporate Authors:

  National Research Council of Canada

  Research Journals
  Ottawa, Ontario K1A 0R6,   Canada 
• Authors:
  • Feda, J
• Publication Date: 1989-11

Media Info

• Features: Figures; References;
• Pagination: p. 517-523
• Serial:
  • CANADIAN GEOTECHNICAL JOURNAL
  • Volume: 26
  • Issue Number: 4
  • Publisher: National Research Council of Canada

Subject/Index Terms

• TRT Terms: Clay; Compression; Creep; Deformation; Microanalysis; Mohr circles; Rheological properties; Sand; Soil mechanics; Soil structure; Soils
• Uncontrolled Terms: Soil deformation
• Old TRIS Terms: Microrheological analysis; Mohr envelope; Physical isomorphism; Soil behavior
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00491968
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 31 1990 12:00AM