Crushing a weak granular material: experimental numerical analyses

Granular materials forming part of embankments, foundations and pavement structures are subjected to both static and dynamic loads. As a result, total or partial particle breakage occurs. Particle breakage causes settlements and a reduction in hydraulic conductivity (Fragaszy & Voss, 1986). Previous research has indicated that granular materials undergoing crushing exhibit a non-linear Mohr-Coulomb failure envelope if the envelope is constructed with the peak values of shear resistance. Therefore the angle of shearing resistance decreases as a consequence of particle crushing (Bolton, 1986; Feda, 2002). On the other hand, recent ring shear tests on carbonate sand presented by Coop et al. (2004) showed crushing without loss of residual angle of internal friction. It seems that crushable granular materials experience a reduction in the internal friction angle as a consequence of particle breakage prior to achieving a constant value of residual strength. The main focus of this study is to understand and produce a visualisation of the evolution of crushing in a weak granular material subjected to a direct shear test. The results from direct shear tests conducted on sugar, and a computer simulation using the discrete element method, are presented. (A)

[1]  Osamu Kusakabe,et al.  TIME-DEPENDENT BEHAVIOR OF CRUSHABLE MATERIALS IN ONE-DIMENSIONAL COMPRESSION TESTS , 2001 .

[2]  D. J. Hagerty,et al.  One‐Dimensional High‐Pressure Compression of Granular Media , 1994 .

[3]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[4]  Iraj Farhoomand,et al.  Compressibility and crushing of granular soil in anisotropic triaxial compression , 1967 .

[5]  J. Feda,et al.  Notes on the effect of grain crushing on the granular soil behaviour , 2002 .

[6]  Jerry A. Yamamuro,et al.  SIGNIFICANCE OF PARTICLE CRUSHING IN GRANULAR MATERIALS , 1996 .

[7]  Malcolm D. Bolton,et al.  On the micromechanics of crushable aggregates , 1998 .

[8]  Richard J. Fragaszy,et al.  Undrained Compression Behavior of Sand , 1986 .

[9]  Denis Vallet,et al.  Numerical model of crushing of grains inside two-dimensional granular materials , 1999 .

[10]  Yukio Nakata,et al.  ONE-DIMENSIONAL COMPRESSION BEHAVIOUR OF UNIFORMLY GRADED SAND RELATED TO SINGLE PARTICLE CRUSHING STRENGTH , 2001 .

[11]  Glenn R. McDowell,et al.  Creep of granular materials , 2003 .

[12]  M. Bolton.  THE STRENGTH AND DILATANCY OF SANDS , 1986 .

[13]  Yukio Nakata,et al.  A probabilistic approach to sand particle crushing in the triaxial test , 1999 .

[14]  Malcolm D. Bolton,et al.  Discrete element simulation of crushable soil , 2003 .

[15]  Richard P. Jensen,et al.  DEM Simulation of Particle Damage in Granular Media — Structure Interfaces , 2001 .

[16]  G. Mandl,et al.  Shear zones in granular material , 1977 .

[17]  T. M. Bodas Freitas,et al.  Particle breakage during shearing of a carbonate sand , 2004 .

[18]  Glenn R. McDowell,et al.  Discrete element modelling of yielding and normal compression of sand , 2002 .