Discrete element modelling of one-dimensional compression of cemented sand

Abstract

It has recently been shown that the onedimensional normal compression of sand can be modelled effectively in three-dimensions using the discrete element method, and that the slope of the compression curve (in log voids ratio-log stress space) is controlled by the size effect on average particle strength. This paper incorporates soil structure by simulating cemented sand, and the effects of interparticle bonding (including bond strength and strength distributions) on the one-dimensional compression behaviour and evolving particle size distributions are investigated. The results show that bonding reduces particle crushing, and it is both the magnitude and distribution of bond strengths that influence the compression curve of the structured material.

Investigating the effects of particle shape on normal compression and overconsolidation using DEM

“…This sample is identical to that used in de Bono and McDowell [6]-although statistically slightly different to the sample used in McDowell and de Bono [1]; however the behaviour will be shown to be the same. The sample has an initial voids ratio of e0 = 0.84, which was as dense as possible without any locked-in contact forces.…”

“…For more discussion on the choice of breakage mechanism, the number of fragments, the influence of different hardening laws and the choice of breakage criteria, readers are directed to prior publications for further information [1,2,12,13]. The default local damping scheme, with a coefficient of 0.7 is used whereby a damping force is applied to all particles.…”

“…and: e = 6 sin 3+sin (12) Assuming that the critical state angle of friction is constant for both compression and extension. Fitting a trendline to the q-p data in Figure 11 It can also be seen in Figure 11 that the stress paths upon reloading do not appear to tend completely towards the original stress paths before unloading.…”

“…In their previous work on normal compression [1,2,6], the authors allowed each particle to split into two new fragments, with the new sphere fragments overlapping enough to be contained with the bounding parent sphere, while obeying conservation of mass. An alternative to using this replacement method would be using agglomerates [7][8][9][10], i.e.…”

“…The simulation procedure used here is identical to that in the above references [1,2,6]; to which the readers are directed to for full details.…”