Pre-failure behaviour of reconstituted peats in triaxial compression
- PDF / 1,128,316 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 77 Downloads / 183 Views
(0123456789().,-volV)(0123456789(). ,- volV)
RESEARCH PAPER
Pre-failure behaviour of reconstituted peats in triaxial compression S. Muraro1
•
C. Jommi1,2
Received: 12 March 2020 / Accepted: 29 June 2020 Ó The Author(s) 2020
Abstract This paper discusses the results of an experimental programme designed to investigate the deviatoric behaviour of peats. The results are obtained from triaxial experiments carried out on reconstituted peat samples. The interpretation of the experimental results follows a hierarchical approach in an attempt to derive the ingredients that an elastic–plastic model for peats should contain, including the yield locus, the hardening mechanism and the flow rule. The results obtained from stress tests along different loading directions show that purely volumetric hardening is not adequate to describe the deviatoric response of peat and that a deviatoric strain-dependent component should be included. The plastic deformation mechanism also depends on the previous stress history experienced by the sample. Stress and strain path dependence of the interaction mechanisms between the peat matrix and the fibres is discussed as a possible physical reason for the observed behaviour. This work offers a relevant set of data and information to guide the rational development and the calibration of constitutive laws able to model the deviatoric behaviour of peats. Keywords Constitutive modelling Peat Triaxial tests List of symbols H Sample height V Sample volume H0 Initial sample height V0 Initial sample volume k Slope of the isotropic normal compression line j Slope of the isotropic unloading–reloading line m Poisson’s ratio e0 Initial void ratio v Specific volume Gs Specific gravity OC Organic content p0 Mean effective stress p0c Pre-consolidation mean effective stress Normalised pre-consolidation mean effective p0c;n stress
p00 p0g q OCR K0 g gK 0 Mf
1
Department of Geoscience and Engineering, Delft University of Technology, Stevinweg 1, 2628 CN Delft, Netherlands
Mg u_a ea er ep eq dep deq epp epq depp depq d b
2
Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
vf vg
& S. Muraro [email protected]
Mean effective stress at the beginning of shear Dummy variable for the plastic potential Deviatoric stress Overconsolidation ratio Coefficient of earth pressure at rest Stress ratio Stress ratio along K0 path Stress ratio associated with the horizontal tangent of the yield locus Stress ratio at critical state Axial displacement rate Axial strain Radial strain Volumetric strain Deviatoric strain Volumetric strain increment Deviatoric strain increment Volumetric plastic strain Deviatoric plastic strain Volumetric plastic strain increment Deviatoric plastic strain increment Dilatancy Inclination to the horizontal of the plastic strain increment vectors Shape coefficient for the yield locus Shape coefficient for the plastic potential
123
Acta Geotechnica
Du a D, D0, D1 W S u0
Excess pore pressure Pore pressure parameter
Data Loading...
