Non-linearity of creep coefficient

This study investigated the non-linear void ratio-log(time) relationship during creep (secondary compression) under a range of loading history. Four long-duration creep tests on reconstituted clay soils from two different sites were performed. Data from tests reported in the literature (six long-duration creep tests on reconstituted marine deposits and three long-duration creep tests on undisturbed soil samples) were also used in this investigation. A creep coefficient function that depends on both the stress state and extent of creep is proposed. According to the function, the creep rate slows down with its progression.