Numerical modelling of plane strain tests on sands using a particulate approach

Abstract

This paper describes the results of a series of numerical plane strain test simulations on a particulate material, carried out using the three-dimensional particle flow code PFC-3D. Samples comprised about 10 000 non-spherical particles, each formed by strongly bonding two spheres together. The simulations demonstrate the ability of such a model to capture the essential macro-features of soil behaviour as observed in laboratory tests, including the dependence of peak strengths on the initial void ratio relative to the critical. The development of strain localisations or shear bands associated with the use of rough loading platens, and the sensitivity of the model to the initial sample porosity, particle shape factor and interparticle friction angle, were also investigated.

Experimental Investigation on the Strength and Failure Behavior of Coal and Synthetic Materials under Plane-Strain Biaxial Compression

“…The residual stages in the synthetic specimen are remarkable and consistent with each other, which in turn verifies the homogeneity of our synthetic materials and confirms that the experimental apparatus has little influence on the test data error. Previous studies also presented a noticeable residual strain range of sand specimens [33]. The residual loading capacity in our study can be explained by the stable zone formed in the center (Figure 8), which is the result of a shear-type failure.…”

“…Although these specimens were compressed to a residual stage, they can keep stable with the existing of this stable zone. Powrie et al [33] and Alshibli et al [34] found similar failure shapes in Ottawa sand and numerical samples, respectively. Powrie et al defined this failure pattern as 'conjugate shear bands'.…”

“…Tao [32] tested the failure strength of soft and hard coal specimens under the PSBSS and they found that greater failure strengths will appear under the PSBSS than those under a uniaxial stress state, for both kinds of coal specimens. Powrie et al [33] and Alshibli et al [34] also found shear failure shapes in Ottawa sand and numerical samples, respectively. Powrie et al defined this failure pattern of geomaterials under the PSBSS as conjugate shear bands.…”

“…Powrie et.al. [33] and Alshibli et.al. [34] found similar failure shapes in Ottawa sand and numerical samples, respectively.…”

Energy Approach Towards Stress-Dilatancy Formulation based on Double Slip-Rotation Rate Concept

“…Herein c, fm and fcv are the angle of dilation, the mobilized friction angle and the friction angle at critical state respectively. Powrie et al (2005) reported a linear relation, which was equivalent to sin c＝c(sin fmsin fcv) with c §0.5, between a measure of dilation šc dened as šc＝tan -1 (dev/de1), the mobilized friction angle f and the critical state friction angle fcv. For plane strain compression, the experimental data based empirical relation fm＝fcv＋0.8c, which can be alternatively approximated as sin c §1.33(sin fm-sin fcv), is``operationally indistinguishable'' from Rowe's stress-dilatancy relation (Bolton, 1986).…”