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

Abstract

Predicting the cyclic response of soils is still challenging in many geotechnical fields, and motivates massive research to shed light on lesser-known aspects of the problem. In this area, the continual efforts on the constitutive modelling of cyclic sand behaviour demand new and reliable dataset for model validation -especially for loading conditions involving many loading cycles ('high-cyclic' loading). In this letter, the recent memory-enhanced bounding surface formulation by Liu et al.(2018a) is considered as a suitable platform to reproduce the high-cyclic response of sands, and its transition into either 'ratcheting' or 'shakedown' behaviour. New evidence of its suitability is found against the latest dataset presented in Park & Santamarina (2018), comprising the results of highcyclic oedometer tests at varying initial/loading conditions. Model-simulations prove in satisfactory agreement with most experimental findings, especially regarding the prediction of so-called 'terminal densities'.

New perspectives on preshearing history in granular soils

“…The SaniSand family of models has attracted increased attention from researchers in the last decades resulting in a significant number of published models, for e.g. 47,[63][64][65][66] . Lastly, the yield surface of this model was reduced even to zero and becomes identical to the stress point itself, and plastic loading occurs for any direction of the stress ratio rate on which the loading and plastic strain rate directions now depend, rendering the model incrementally non-linear 67 .…”

Influence of recent and long-lasting loading history on the cyclic behaviour of sand: confrontation of novel experimental results and established constitutive laws

“…The SaniSand family of models has attracted increased attention from researchers in the last decades resulting in a significant number of published models, for e.g. [2, [22][23][24]44]. Lastly, the yield surface of this model was reduced even to zero and becomes identical to the stress point itself, and plastic loading occurs for any direction of the stress ratio rate on which the loading and plastic strain rate directions now depend, rendering the model incrementally nonlinear A.4 Hypoplasticity with Historiotropic Yield Surface (Hypo+YS)…”

From cyclic sand ratcheting to tilt accumulation of offshore monopiles: 3D FE modelling using SANISAND-MS

“…Such a goal is pursued through the application of 120 SANISAND-MS, a constitutive model recently proposed by 121 Liu et al (2019b) to enhance the simulation of high-cyclic 122 sand ratcheting (Wichtmann, 2005;di Prisco & Mortara, 2013), 123 and therefore the assessment of foundation serviceability under 124 cyclic loading. Following recent constitutive modelling work 125 (Liu et al, 2019b;Liu & Pisanò, 2019;Liu et al, 2020), 126 SANISAND-MS is here adopted for the first time to tackle a 127 3D boundary value problem.…”

“…m M and m are related to the radii of memory and yield surface, respectively, b 0 is a factor depending on the current void ratio and mean effective stress, while µ 0 is a model parameter governing strain accumulation (ratcheting) under drained cyclic loading. At variance with the first SANISAND-MS formulation (Liu et al, 2019b), the yield back-stress ratio α α α and its projections onto bounding (α α α b ), dilatancy (α α α d ), and critical (α α α c ) surfaces are used here as in SANISAND2004see Liu & Pisanò (2019) and Liu (2020).…”