THE INTERPRETATION OF IN SITU SOIL TESTS
This paper was given as the twenty-fourth Rankine Lecture of the British Geotechnical Society. The purposes of in situ testing are set out, and the difficulties of the interpretation of the observations are emphasized. These difficulties are due to the complex behaviour of soils together with the lack of control and of choice of the boundary conditions in any field test. One notable exception is the pressuremeter test, from which soil properties can be derived directly without recourse to empirical correlations. The discussion is concentrated on the measurement of undrained shear strength. The results obtained from different tests (triaxial, plane strain, direct simple shear, pressuremeter and vane) are compared by expressing them in terms of the undrained strength ratio as a function of the friction angle. Special attention is paid to tests in which the principal axes of stress and of strain increment are free to rotate. In such tests, uncertainty exists regarding the definition of failure and the planes of maximum stress obliquity. To derive these functions Matsuoka's failure criterion is used. As a consequence a theoretical hierarchy of strengths is established which agrees qualitatively with experimental evidence. The importance to a designer of this variety of strengths is emphasized. A study is made of the piezocone and the interpretation of the pore pressures in terms of the overconsolidation ratio of the clay tested. A plea is made for the standardization of the equipment, the operation and the interpretation of in situ tests to obtain maximum benefit from them. (TRRL)
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/issn/00168505
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Corporate Authors:
Institution of Civil Engineers
One Great George Street, Westminster
London, United Kingdom SW1P 3AA -
Authors:
- Wroth, C P
- Publication Date: 1984-12
Media Info
- Features: Figures; References; Tables;
- Pagination: p. 449-489
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Serial:
- GEOTECHNIQUE
- Volume: 34
- Issue Number: 4
- Publisher: Thomas Telford Limited
- ISSN: 0016-8505
Subject/Index Terms
- TRT Terms: Clay; Cone penetrometers; Direct shear tests; Evaluation and assessment; Failure; Field tests; Friction; Measurement; Mechanical vanes; Overconsolidation; Pore pressure; Pore water pressures; Pressure gages; Saturated soils; Soil mechanics; Soil tests; State of the art reports; Strain (Mechanics); Strength of materials; Stresses; Tests; Theory; Triaxial shear tests; Undrained shear strength; Vane shear tests
- Uncontrolled Terms: Failure criterion; Friction angle; Plane strain; Undrained soils
- Old TRIS Terms: Insitu methods; Soil behavior; Strains
- ITRD Terms: 4177: Clay; 5460: Coefficient of friction; 6178: Cone penetrometer; 9020: Evaluation (assessment); 6226: In situ; 6136: Measurement; 5762: Pore water pressure; 6128: Pressiometer; 8588: State of the art report; 5544: Strength (mater); 6255: Test; 9078: Theory; 5566: Triaxial; 5782: Undrained soil; 6158: Vane
- Subject Areas: Geotechnology; Highways;
Filing Info
- Accession Number: 00395097
- Record Type: Publication
- Source Agency: Transport Research Laboratory
- Files: ITRD, TRIS
- Created Date: Aug 31 1985 12:00AM