Memory Surface Hardening Model for Granular Soils under Repeated Loading Conditions

Abstract

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms 1 The prediction of the stress-strain response of granular soils under large numbers of repeated 19 loading cycles requires subtle changes to existing models, although the basic framework of 20 kinematic hardening/bounding surface elasto-plasticity can be retained. Extending an existing 21 model, an extra memory surface is introduced to track the stress history of the soil. The 22 memory surface can evolve in size and position according to three rules which can be linked 23 with physical principles of particle fabric and interaction. The memory surface changes in 24 size and position through the experienced plastic volumetric strains but it always encloses the 25 2 current stress state and the yield surface; these simple rules permit progressive stiffening of 26 the soil in cyclic loading, the accurate prediction of plastic strain rate accumulation during 27 cyclic loading, and the description of slightly stiffer stress-strain response upon subsequent 28 monotonic reloading. The implementation of the additional modelling features requires the 29 definition of only two new constitutive soil parameters. A parametric analysis is provided to 30 MEMORY SURFACE HARDENING MODEL FOR GRANULAR SOILS UNDER 1 REPEATED LOADING CONDITIONSshow model predictions for drained and undrained cyclic loading conditions. The model is 31 validated against available tests on Hostun Sand performed under drained triaxial cyclic 32 loading conditions with various confining pressures, densities, average stress ratios and cyclic 33 amplitudes. 34

Local and Global Volumetric Strain Comparison in Sand Specimens Subjected to Drained Cyclic and Monotonic Triaxial Compression Loading

“…While the achievement of precise and accurate measurement of specimen deformations and the proper account of nonuniformities and localization issues are still ongoing research topics, most of the previous experimental work has concentrated on the monotonic shearing behavior of soils (Desrues 1984;Colliat-Dangus, Desrues, and Foray 1988). The research reported here aimed to expand the current state of the knowledge by exploring the development of nonuniformities in sand specimens subjected to up to 4,000 drained compressive load cycles in the triaxial apparatus, as part of experimental and constitutive modeling research at the University of Bristol, United Kingdom (Corti et al 2016). The nonuniformity of deformations across the specimen has been examined by comparing volume changes using both global and local measurements.…”

Prediction of oedometer terminal densities through a memory-enhanced cyclic model for sand

“…Relevant test settings considered are all summarised in Dafalias & Manzari (2004), and enhanced according to the notion of memory surface (Corti et al, 2016). The memory locus is introduced to track fabric effects, and hence simulate realistic sand behaviour under high-cyclic loading.…”

“…Published online at www.geotechniqueletters.com * Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN Delft (The Netherlands) particularly of the new memory-enhanced bounding surface formulation for sand by Liu et al (Liu et al, 2018a,b). The model belongs in the well-known family of criticalstate SANISAND models (Dafalias & Manzari, 2004), and relies on the use of an additional locus ('memory surface') to capture fabric-related ratcheting/shakedown phenomena (Corti et al, 2016). An opportunity for building further trust about the model has been very recently offered by Park & Santamarina (2018), who published novel data concerning dry sand compaction in high-cyclic oedometer tests (i.e.…”

Enhanced plasticity modelling of high-cyclic ratcheting and pore pressure accumulation in sands

“…The reference SANISAND04 model, which is build upon a critical state and bounding surface plasticity framework, includes a fabric-dilatancy tensor to reproduce soil fabric effects. The suitability of combining bounding surface theory and memory surface concept has been proven by the work of Corti et al (2016). Soil fabric and its evolution are recorded by a newly introduced memory surface, enclosing a stress region which the soil feels to have already experienced and thus characterised by high stiffness.…”