Rate dependent shear and consolidation of remoulded San Francisco Bay mud

Results of an experimental program on Remoulded San Francisco Bay Mud (RSFBM), and how these results are estimated by the rate dependent elastic-viscoplastic constitutive model described by Kutter and Sathialingam, is presented. The program included 1-dimensional and triaxial consolidation tests with load increment durations equal to 24 hrs. and load increment ratio equal to 1, creep tests on samples at over-consolidation ratios (OCR) equal to 1, 2, and 8, strain controlled undrained triaxial compression tests on samples at OCR equal to 1, 2, and 8 with shearing strain rates equal to 0.003;Experimental results showed the undrained shear strength of normally consolidated (NC) RSFBM increases about 5% to 10% per logarithmic cycle of strain rate. Results also showed almost identical gains in undrained shear strength for OCR = 2 and OCR = 8. In addition, results showed a well defined relation between the undrained shear strength of NC RSFBM (sheared at a given strain rate) and the strength of over-consolidated RSFBM (sheared at the same strain rate). The effect of OCR is described by the Stress History And Normalized Soil Engineering Properties method, and by the Kutter-Sathialingam model. The effects of creep on the undrained shear strength and slope of the critical state line (M) is also presented.;Experimental results also showed that the secondary compression index ;Finally, the rate dependent elastic-viscoplastic constitutive model proposed by Kutter and Sathialingam was found to be relatively accurate in predicting how undrained shear strength varies with strain rate. The model however, was less accurate when predicting the effective stress path. Some improvements to the Kutter-Sathialingam model are suggested.