THE MEASUREMENT OF SOIL STIFFNESS IN THE TRIAXIAL APPARATUS

This paper describes a simple technique for accurately measuring the mean local axial strains of triaxial samples over a central gauge length. The technique makes use of an axial displacement gauge which is a development of one devised by Burland & Symes which makes use of electrolytic levels. The device can resolve to less than 1 micrometre over a range of 15 mm, is simple to mount on the specimen and is not damaged when the sample is taken to failure. The results of undrained triaxial tests are presented for a wide spectrum of soil types ranging from sands through intact, reconstituted and remoulded low plasticity till, undisturbed London clay to intact unweathered chalk. The test results show that conventional external measurements of displacement contain errors which are frequently so large that their use in the determination of soil stiffness at working levels of stress is invalid. The errors mainly result from tilting of the sample, bedding at the end platens and the effects of compliance in the apparatus. Although much more experimental work is required before general conclusions can be drawn about the small strain behaviour of soils the results presented lead to some important observations on the undrained stiffness, linearity and yielding behaviour of soils at small strains. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00168505
• Corporate Authors:

  Institution of Civil Engineers

  One Great George Street, Westminster
  London,   United Kingdom  SW1P 3AA
• Authors:
  • JARDINE, R J
  • Symes, M J
  • Burland, J B
• Publication Date: 1984-9

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 323-340
• Serial:
  • GEOTECHNIQUE
  • Volume: 34
  • Issue Number: 3
  • Publisher: Thomas Telford Limited
  • ISSN: 0016-8505

Subject/Index Terms

• TRT Terms: Axis; Chalks; Clay; Compliance; Deformation; Errors; Failure; Linearity; Measurement; Measuring instruments; Mechanical strain; Motion; Samples; Saturated soils; Soils; Stiffness; Strain gages; Structural analysis; Structural mechanics; Test procedures; Till; Triaxial shear tests; Undrained shear tests
• Uncontrolled Terms: Structural behavior; Triaxial testing machine; Undrained soils; Undrained tests
• Old TRIS Terms: Strains; Yield
• ITRD Terms: 6155: Apparatus (measuring); 6405: Axis; 4198: Boulder clay; 4120: Chalk; 4177: Clay; 5595: Deformation; 6440: Error; 6136: Measurement; 5483: Movement; 6251: Sample (mater); 4156: Soil; 5931: Stiffness; 5562: Strain gauge; 6288: Test method; 5566: Triaxial; 5782: Undrained soil
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00394629
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Jul 31 1985 12:00AM