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Size Effect in Simple Shear Testing.
Amer, M. I.; Aggour, M. S.; Kovacs, W. D.
National Bureau of Standards (NEL), Gaithersburg, MD. Center for Building Technology., November 1984, 66 p.
Simple shear testing is considered to be one of the most appropriate ways of reproducing in the laboratory the stresses that would be experienced by an element of soil subjected to earthquake loading. The main drawback concerns the sample size, in that for a small sized sample, the test results are affected by the non-uniformity of the stress in the sample. To investigate the sample size effect on the primary dynamic soil properties, namely the shear modulus and damping, a large simple shear apparatus was constructed. A total of 144 tests were performed to study the size effect and to choose an ideal size for testing dry sand. The suggested size gave results of shear modulus and damping independent of the sample boundaries. Formulas and charts for correction factors were also developed to be used to correct the results from simple shear tests on samples having sizes other than the ideal size proposed herein.
Damping; Shear properties; Finite element analysis; Earthquake engineering; Shear tests; Soil mechanics