Pre-failure behaviour of reconstituted peats in triaxial compression     

Muraro  S.  Jommi  C. 《Acta Geotechnica》2021,16(3):789-805

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.

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On the use of infinite elements in the analysis of two-dimensional layered elastic systems via discretized integral equations     

Cristina Jommi  Giorgio Novati 《Computers and Geotechnics》1989,8(4):269-288

A boundary integral equation approach is presented for the two-dimensional plane strain analysis of horizontally layered elastic systems resting on a rough and rigid base. The validity of Somigliana identity for unbounded layers is discussed and an Infinite Boundary Element is proposed in order to take into account the lateral unboundedness of the physical problem in the discretized equations. This element is implemented in a computer code based on a successive stiffness solution procedure. A series of numerical tests concerning single- and multi-layered problems is illustrated, and the performance of the proposed solution method is compared with that of more traditional boundary element and finite element techniques.  相似文献   

Accounting for evolving pore size distribution in water retention models for compacted clays          下载免费PDF全文

Gabriele Della Vecchia  Anne‐Catherine Dieudonné  Cristina Jommi  Robert Charlier 《国际地质力学数值与分析法杂志》2015,39(7):702-723

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Numerical integration of an elastic–viscoplastic constitutive model for dry metamorphosed snow     

Silene Cresseri  Francesco Genna  Cristina Jommi 《国际地质力学数值与分析法杂志》2010,34(12):1271-1296

A constitutive model for dry metamorphosed snow is proposed, within the framework of elasto‐viscoplasticity, which is able to reproduce the most relevant features of the macroscopic behaviour of snow, particularly its time and rate dependency. The basic ideas for modelling stem from the conceptual forms proposed for bonded geomaterials, such as cemented soils or soft rocks. The high viscosity of snow is accounted for by adopting an overstress approach, suitably modified. An evolution law for the curvature‐driven process of sintering, by which intergranular ice necks form and grow, is established. The system of constitutive equations is then numerically integrated via a fully implicit time stepping scheme. Selected results from finite element simulations of laboratory tests, available in the literature, are presented. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献