DEM Modeling of Particle Breakage in Silica Sands under One-Dimensional Compression
A Discrete Element Method (DEM) model is developed to study the particle breakage effect on the one-dimensional compression behavior of silica sands. The ‘maximum tensile stress’ breakage criterion considering multiple contacts is adopted to simulate the crushing of circular particles in the DEM. The model is compared with published experimental results. Comparison between the compression curves obtained from the numerical and experimental results shows that the proposed method is very effective in studying the compression behavior of silica sands considering particle breakage. The evolution of compression curves at different stress levels is extensively studied using contact force distribution, variation of contact number and particle size distribution curve with loading. It is found that particle breakage has great impact on compression behavior of sand, particularly after the yield stress is reached and particle breakage starts. The crushing probability of particles is found to be macroscopically affected by stress level and particle size distribution curve, and microscopically related to the evolutions of contact force and coordination number. Once the soil becomes well-graded and the average coordination number is greater than 4 in two-dimension, the crushing probability of parent particles can reduce by up to 5/6. It is found that the average contact force does not always increase with loading, but increases to a peak value then decreases once the soil becomes more well-graded. It is found through the loading rate sensitivity analysis that the compression behavior of sand samples in the DEM is also affected by the loading rate. Higher yield stresses are obtained at higher loading rates.
Key Wordsparticle breakage silica sand particle breakage criterion one-dimensional compression Discrete Element Method (DEM)
Unable to display preview. Download preview PDF.
- 1.Terzaghi, K. and Peck, R.B., Soil Mechanics in Engineering Practice. 1st Ed., John Wiley & Sons Inc., New York, 1948.Google Scholar
- 6.Otani, J., Mukunoki, T. and Sugawara, K., Evaluation of particle crushing in soils using X-ray CT data. Soils and Foundations, 2005, 45(1): 99–108.Google Scholar
- 14.O’Sullivan, C., Particulate Discrete Element Modelling: A Geomechanics Perspective. Taylor and Francis, 2011.Google Scholar
- 29.Itasca, Two Dimensional Particle Flow Code: Software Manual (Version 4.0). Itasca Consulting Group Inc., Minneapolis, Minnesota, 2008.Google Scholar
- 32.Guyon, E. and Troadec, J.P., The mechanics of sand. Editions Odile Jacob Sciences, 1994, 2: 86–97.Google Scholar
- 37.Jardine, R.J., Lehane, B.M. and Everton, S.J., Friction coefficient for piles in sands and silts. Offshore Site Investigation and Foundation Behaviour, Society for Underwater Technology, London, UK, 1993: 661–677.Google Scholar