Elasto-viscoplastic modelling of a porous chalk

Numerical Modeling of the Effect of Carbon Dioxide Sequestration on the Rate of Pressure Solution Creep in Limestone: Preliminary Results

“…The deformation of chalk, both dry and in the presence of fluids, has been widely investigated experimentally. Most of the published work is based on chalk deformation data that have been interpreted solely in terms of mechanical processes (e.g., Botter, 1985;Da Silva et al, 1985;Jones and Leddra, 1989;Monjoie et al, 1990;Shao et al, 1994;Piau and Maury, 1995;Schroeder and Shao, 1996;Homand et al, 1998;Risnes and Flaageng, 1999). Recently, however, a few studies have examined chalk-fluid deformation within the context of chemical processes associated with PSC (Hellmann et al, 2002a(Hellmann et al, , 2002bHeggheim et al, in press).…”

An elastoplastic coupling mechanical model for hard and brittle marble with consideration of the first stress invariant effect

“…In a study on elastoplastic coupling based on Il'iushin's postulate, Dafalias confirmed a theory that the elastic modulus of geotechnical materials varies with the internal variables (Dafalias, 1977a(Dafalias, , 1977b. Moreover, previous studies have also shown that the variation of elastic modulus of brittle rock is closely linked with the confining pressure or minimum principal stress (Brown, Bray, & Santarelli, 1989;Chen, Shao, Zhu, & Duveau, 2012;Lionço & Assis, 2000;Santarelli, Brown, & Maury, 1986;Shao, Bederiat, & Schroeder, 1994;Shao & Henry, 1990, 1991Xie & Shao, 2012;You, 2003). Therefore, the elastic modulus of brittle rocks is obviously dependent on both the plastic deformation and stress, however, very few studies have referred to the elasticity modulus E being effected by both the plastic deformation and stress.…”

Evaluation of the behaviour of the lateral boreholes in the Gorm chalk field

“…Various visco-plasticity models have been proposed to simulate time-dependent deformation of soft rocks, like chalk [21][22][23][24] . These models together with many other models widely used for soft rocks are formulated based on overstress concept using different formulations relying on the relative position of stress point and reference or yield surface in stress space.…”

“…However, these models often lack physical meanings for the model parameters and consistency of yield surfaces. In an alternative way, visco-plasticity can also be modeled via the consistent condition of nonstationary yield surfaces in which the plastic hardening rule is formulated with the consideration of both strain rate and viscoplastic deformation [21,[25][26][27][28] .…”