The paper presents the result of an experimental investigation on the stiffness anisotropy of a reconstituted clay consolidated in a stress path apparatus fitted with both vertical and horizontal bender elements. The tested samples were consolidated under different stress ratios up to pressures higher than those usually achieved in similar studies. In this way the influence of long anisotropic stress paths on the clay stiffness was highlighted. In particular, the variations oldie shear stiffness moduli G(ij) (ij defines the plane in which shearing is being considered) were continuously monitored, to characterize the evolution of the clay stiffness anisotropy. The material under study was the medium plasticity (PI = 24-25%) reconstituted Lucera clay (Southern Italy). It was subjected to isotropic, anisotropic (radial path with constant stress ratio eta = 0.3; 0.6 and 0.8), and eta-combined stress paths (eta = 0.8-0.1). The testing programme was designed in order to identify a framework of variation for both G(hh) and G(hv) under either isotropic or anisotropic conditions. It is deduced that the different plastic straining resulting from the imposition of different virgin radial paths tends to modify the original level of elastic stiffness anisotropy.
|Autori interni:||COTECCHIA, Federica|
|Titolo:||Elastic stiffness anisotropy of clay samples radially compressed along different stress ratio triaxial paths|
|Data di pubblicazione:||2008|
|Nome del convegno:||4th International Symposium - Deformation Characteristics of Geomaterials|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|