Strength attenuation effects on rate-dependent law of stress development of frozen sand

Abstract

In this paper, effects of strength attenuation on stress development tendency (strain hardening or softening) under different strain rate were analysed. A series of triaxial creep and constant strain rate compression tests were conducted on frozen sand samples. Based on test results analysis, it was indicated that strength attenuation function is usually underestimated with the creep test results. After correcting the function with constant strain rate test results, it was verified that the calculation accuracy of a rate-dependent model with strength attenuation proposed by the authors is improved greatly. Further theoretical analysis indicates that the development tendency of stress (strain hardening or softening) under different constant strain rates is dependent upon relative position between stress point and failure line in p−q space, and strain softening degree is dependent on applied strain rate and the law of strength attenuation.