Steady-state lines of sand–silt mixtures

Abstract

The steady-state lines (SSLs) for sand–silt mixtures with various fines contents (0%, 5%, 10%, 15%, 20%, 30%, 50%, 70%, and 94%) were studied. It was indicated that the location of the SSL in the e–p′ space is different for each mixture, but the SSLs are parallel. In the e – ln p′ plot, the SSLs are similar for the mixtures with a fines content of less than the transitional fines content (TFC) when tested under drained and undrained conditions and the intergranular and interfine void ratios are used. The data diverge when the fines contents are equal to or greater than the TFC, even though the interfine void ratios are used. The results of the tests conducted under drained and undrained conditions produced a unique SSL in the p′–q space for each material. Different SSLs in the p′–q space were observed for the studied materials, and the friction angle at steady state varied in the range of 37.3°–42.2°. The study showed that the SSLs can be represented by one line in tests under drained conditions if the fines contents are less (0%–30%) than the TFC and the corrected intergranular void ratios are used. The lines can also be represented by one line for sand–silt mixtures with high fines contents (50%–94%) if the corrected interfine void ratios are used instead of void ratios. Key words: steady-state line, sand–silt mixtures, transitional fines content, drained and undrained triaxial tests.