Methodology for Estimating Creep Deformation from Consolidation Deformation in 1D Compression

Abstract

In geotechnical engineering, characterization of time-dependent behavior of clayey soils under one-dimensional (1D) constant stress has been controversial. In some special cases, the creep deformation is insignificant during primary consolidation, and is assumed to start at the end of primary consolidation. In the general case, the total deformation results from a coupled process involving both hydromechanical (mechanical loading) and viscous (creep) effects. Creep deformation commences at the start of the loading. This paper proposes a methodology to decouple the creep-deformation component from the total deformation measured in oedometer tests. This methodology is based on the concept of isotache [i.e., there exists a unique relationship among void ratio, effective stress, and time factor (Hypothesis B)]. The methodology was used to analyze the 1D compression data of reconstituted Regina clay samples. It was demonstrated that this methodology is capable of determining the intrinsic properties of a 1D normally consolidated curve (independent of sample thickness and duration of end of primary consolidation) and creep behavior.