Abstract
The stress–dilatancy relationship is a key point to capture the evolution of both strains and excess pore pressure during an undrained creep of natural soft clay. This paper focuses on investigating the stress dilatancy of natural soft clay during an undrained creep. Undrained triaxial creep tests are performed on K0-consolidated and isotropically consolidated samples of a typical Chinese soft marine clay with different stress levels. A unique stress–dilatancy curve is obtained from all test results. Several typical stress–dilatancy relations for soils are discussed, comparing them with experimental results. A common modification method for the stress dilatancy of sand is adopted and discussed for clay. All comparisons demonstrate that modified dilatancy equations can describe the stress–dilatancy relationship during an undrained creep. The modified dilatancy equation with the inclination of a potential surface seems to better describe the whole trend, and is suitable for natural soft clay.
Highlights
Because of the low permeability of soft clay, an excess pore water pressure is usually generated during the period of construction, during which foundation soils are deforming simultaneously under undrained conditions
This continuing undrained creep may often result in a collapse of the clay foundation, which implies that the undrained shear strength can be significantly reduced with time, as investigated through undrained triaxial creep tests by various researchers (Casagrande and Wilson 1951; Walker 1969; Holzer et al 1973; Vaid and Campanella 1977; Adachi and Oka 1982; Yin et al 2002; Hinchberger and Rowe 2005; Yin and Hicher 2008; Yin et al 2010b, c, 2011; Yin and Karstunen 2011; Desai et al 2011; Taechakumthorn and Rowe 2012)
A series of undrained triaxial creep tests were performed on identical K0-consolidated clay samples under different deviatoric stress levels with stress ratios q=qpeak varying from 0.88 to 1.0
Summary
Because of the low permeability of soft clay, an excess pore water pressure is usually generated during the period of construction (e.g., for a high filled embankment, or a foundation for a building), during which foundation soils are deforming simultaneously under undrained conditions. The stress dilatancy is a key point to accurately describe the undrained creep behavior (the evolution of both strains and excess pore pressure with time) of clay. For this purpose, undrained triaxial creep tests are performed on a typical Chinese soft marine clay.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
