CONFINING PRESSURE REDUCTION EXPERIMENTS: A NEW METHOD FOR MEASURING FRICTIONAL STRENGTH OVER A WIDE RANGE OF NORMAL STRESS

This paper describes a new type of friction experiment in a triaxial apparatus, called the confining pressure (p-c) reduction experiment, which permits the determination of frictional strength over a wide range of normal stress from a single test. The test is simple and requires little modification to the ordinary experimental set-up, and yet it enables one to collect many data easily during one experiment. The specimen is left under a differential stress in the test, and then p-c is lowered at various rates with the loading motor turned off. The differential stress supported by the specimen is removed mostly by a sequence of abrupt slip events during this p-c reduction. Stress at the onset of each event roughly gives the frictional strength at that normal stress. Frictional strength also can be estimated when the differential stress is removed by stable slip. Results for Tennessee sandstone with no gouge and with chlorite gouge are described as examples. A similar experiment can be conducted in a direct shear test, and the tests are ideal for quick measurements of the frictional strengths. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01489062
• Corporate Authors:

  Pergamon Press, Incorporated

  Headington Hill Hall
  Oxford OX30BW,    
• Authors:
  • Shimamoto, T
• Publication Date: 1985-8

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 227-236
• Serial:
  • Intl J of Rock Mech & Mining Sci & Geomechanic Abs
  • Volume: 22
  • Issue Number: 4
  • Publisher: Pergamon Press, Incorporated
  • ISSN: 0148-9062

Subject/Index Terms

• TRT Terms: Confining pressure; Friction; Loads; Measurement; Pressure; Rocks; Sandstones; Shear strain; Slip (Fluid mechanics); Strength of materials; Stresses; Test procedures; Triaxial shear tests
• Uncontrolled Terms: Slips; Triaxial testing machine
• Old TRIS Terms: Frictional properties; Frictional strength; Normal stress; Pressure reduction
• ITRD Terms: 5452: Friction; 5567: Load; 6136: Measurement; 4154: Rock; 4104: Sandstone; 5544: Strength (mater); 5575: Stress (in material); 6288: Test method; 5566: Triaxial
• Subject Areas: Geotechnology; Highways; I43: Rock Mechanics;

Filing Info

• Accession Number: 00451377
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Aug 27 2004 9:58PM