The consolidation of soils exhibiting creep under constant effective stress

Abstract

A theory of consolidation is developed for soils exhibiting creep under constant effective stress. The mathematical model for the theory is based on the soil model described by Bjerrum (1967). Equations governing the behaviour of the model are presented and a numerical procedure which can be used to obtain a solution to the equations in terms of both pore pressures and volume changes is described. As a check on the reliability of the solution, the strains and pore pressures measured in 1·75, 7·5 and 45 cm high oedometer specimens are compared with those predicted by the theory. Remarkable agreement can be observed. In addition, the theory is shown to give a reliable estimate of the settlementtime histories of three building structures in Drammen, Norway. On développe une théorie de la consolidation des sols qui montrent des effets de fluage sous l'influence d'une contrainte efficace constante. Le modèle mathématique de la théorie est basé sur le modèle de sol décrit par Bjerrum (1967). On présente les équations qui régissent le comportement du modèle et on décrit une méthode numérique qui peut être utiliée pour obtenir une solution des équations sous la forme de changements de pression de pore et de changements dc volume. Pour vérifier l'exactitude de la solution, on a compare les mesures des déformations et des pressions de pore sur des échantillons d'oédométre 1.75; 7,5 et 45 cm aux résultats prédits par la théorie. On a obtenu un accord remarquable. En outre, on montre que la théorie donne un estimé assez sur des courbes tassement-temps pour trois structures de constructions à Drammen en Norvège.

Fractal model for virgin compression of pure clays

“…Eq. (19) is the same as that proposed by Nishida (1956), Hansen (1969), Garlanger (1972), Mesri et al (1975), Sridharan and Jayadeva (1982), Nagaraj and Srinivasa Murthy (1986) and Jose et al (1989). The virgin compression curves for some reconstituted clays covering a wide range of plasticity are shown in Figs.…”

“…The plastic, elastic bulk moduli and the hardening function derived from e-ln p relation are based on the infinitesimal strain which is useful only for the description of the elastic body and are not pertinent to elastoplastic constitute equations for a large deformation (Hashiguchi, 1995). Due to the above-mentioned shortcomings of e-ln p relation, two types of power formulation for virgin compression have been used to describe the full relationship between volume and pressure over a wide stress range, one is log e-log p linear formation (Nishida, 1956;Hasen, 1969;Garlanger, 1972;Mesri et al, 1975;Sridharan and Jayadeva, 1982;Nagaraj and Srinivasa Murthy, 1986;Jose et al, 1989) and another is log m-log p (Hashiguchi, 1977;Hashiguchi, 1995;Butterfield, 1979;Juarez-Badilo, 1981;Den Haan, 1992). All existing power formulations of the virgin compression curve for pure clays are empirical and without physical basis, all the parameters are determined by regression analysis.…”

Numerical simulations of the reuse of piled raft foundations in clay

“…One of the earliest creep laws developed was that by Buisman [8] for one-dimensional compression of clays. Subsequent advances were made by Bjerrum [4], Sing and Mitchell [48], Garlanger [18], Leroueil et al [32], Mesri and Castro [37], and Yin and Graham [56]. More theoretical formulations were later documented by Sekiguchi [43], Adachi and Oka [1], and Borja and Kavazanjian [7].…”

“…The fundamentals associated with this model are based on the work of Buisman [8], Š uklje [50], Bjerrum [4] and Garlanger [18]. This model accounts for some of the basic mechanical features of soils such as stress-dependent stiffness, MohrCoulomb failure criterion, distinction between primary loading and unloading-reloading, time-dependent compression behaviour and associated flow rule for plastic strains.…”

Simulation of regional land subsidence in the southern Yangtze Delta

“…Although there is some theoretical research on the last type of deformation in soil mechanics literatures, it is very difficult to be applied to land subsidence. Gu et al [2] constructed the flow and subsidence models on the basis of the visco-elasto-plastic constitutive law developed by Bjerrum [8] and Garlanger [9] to study the deformation of upper soil units. The Bjerrum and Garlanger models divided the strain into instantaneous elastic, instantaneous plastic and creep strain, and assumed that the creep occurred under constant effective stress.…”