Depositional age effects on strain-rate dependent one-dimensional consolidation characteristics of marine clays in Kobe Bay area

Abstract

In this paper, the coupled effects of strain-rate as well as depositional age on one-dimensional consolidation characteristics of marine clays in Kobe Bay area are in detail discussed, based on the results of consolidation tests performed in the laboratory with a mission to predict long-term settlement of Holocene and Pleistocene clay deposits. Prior to a series of constant-rate of strain (CRS) consolidation test, a high quality of the marine clay samples was manifested by comparing the elastic shear modulus of laboratory samples against the comparable modulus when measured in the field. In the CRS tests performed using the clay samples spanning over a wide range of sedimentation age, the yield stress increased as the strain-rate increased. Moreover, the strain-rate dependency was more significant for younger clay samples. The effect of depositional age on the over-consolidation ratio (OCR) was successfully quantified by introducing the rate dependent coefficient, α.