Utili, S. and Nova, R.. (2008) DEM analysis of bonded granular geomaterials. International Journal for Numerical and Analytical Methods in Geomechanics, Vol.32 (No.17). pp. 1997-2031. ISSN 0363-9061

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Abstract

In this paper, the application of the distinct element method (DEM) to frictional cohesive (c, ϕ) geomaterials is described. A new contact bond model based on the Mohr–Coulomb failure criterion has been implemented in PFC2D. According to this model, the bond strength can be clearly divided into two distinct micromechanical contributions: an intergranular friction angle and a cohesive bond force. A parametric analysis, based on several biaxial tests, has been run to validate the proposed model and to calibrate the micromechanical parameters. Simple relationships between the macromechanical strength parameters (c, ϕ) and the corresponding micromechanical quantities have been obtained so that they can be used to model boundary value problems with the DEM without need of further calibration. As an example application, the evolution of natural cliffs subject to weathering has been studied. Different weathering scenarios have been considered for an initially vertical cliff. Firstly, the case of uniform weathering has been studied. Although unrealistic, this case has been considered in order to validate the DEM approach by comparison against analytical predictions available from limit analysis. Secondly, non-uniform weathering has been studied. The results obtained clearly show that with the DEM it is possible to realistically model boundary value problems of bonded geomaterials, which would be overwhelmingly difficult to do with other numerical techniques.

Item Type:	Journal Article
Subjects:	Q Science > QE Geology T Technology > TA Engineering (General). Civil engineering (General)
Divisions:	Faculty of Science > Engineering
Library of Congress Subject Headings (LCSH):	Granular materials -- Mathematical models, Slopes (Soil mechanics) -- Stability
Journal or Publication Title:	International Journal for Numerical and Analytical Methods in Geomechanics
Publisher:	John Wiley & Sons, Ltd.
ISSN:	0363-9061
Date:	10 December 2008
Volume:	Vol.32
Number:	No.17
Number of Pages:	35
Page Range:	pp. 1997-2031
Identification Number:	10.1002/nag.728
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
Funder:	Italy. Ministero dell'istruzione, dell'università e della ricerca [ Ministry of Education, Universities and Research (Italy)] (MIUR), Ce.A.S., Itasca Consulting Group
References:	1. Bardet JP, Proubet J. A numerical investigation of the structure of persistent shear bands in granular media. G´eotechnique 1991; 41:599–613. 2. Rothenburg L, Bathurst RJ. An analytical study of induced anisotropy in idealized granular materials. G´eotechnique 1989; 39:601–614. 3. Calvetti F, Emeriault F. Interparticle forces distribution in granular materials: link with the macroscopic behaviour. Mechanics of Cohesive-Frictional Materials 1999; 4:247–279. 4. Cheng YP, Nakata Y, Bolton MD. Discrete element simulation of crushable soil. G´eotechnique 2003; 53:633–641. 5. Cheng YP, Bolton MD, Nakata Y. Crushing and particle deformation of soils simulated using DEM. G´eotechnique 2004; 54:131–141. 6. Itasca Consulting Group. Particle Flow Code in 2-D (PFC-2D) : User’s Manual, Version 3.0. 2004. 7. Potyondy DO, Cundall PA. A bonded-particle model for rock. International Journal of Rock Mechanics and Mining Sciences 2004; 41:1329–1364. 8. Jiang M, Yu H, Leroueil S. A simple and efficient approach to capturing bonding effect in naturally microstructured sands by discrete element method. International Journal for Numerical Methods in Engineering 2006; 69: 1158–1193. 9. Jiang M, Yu H, Harris D. Bond rolling resistance and its effect on yielding of bonded granulates by DEM analyses. International Journal for Numerical and Analytical Methods in Geomechanics 2006; 30:723–761. 10. Taboada A, Estrada N, Radjai F. Additive decomposition of shear strength in cohesive granular media from grain scale interactions. Physical Review Letters 2006; 97:098302 1–4. 11. Delenne JY, Youssoufi MS, Cherblanc F, B´enet JC. Mechanical behaviour and failure of cohesive granular materials. International Journal for Numerical and Analytical Methods in Geomechanics 2004; 28:1577–1594. 12. Utili S. Evolution of natural slopes subject to weathering an analytical and numerical study. Ph.D. Thesis, Politecnico di Milano, Milano, 2004. 13. Hutchinson JN. The response of London Clay cliffs to differing rates of toe erosion. Geologia Applicata e Idrogeologia 1973; 7:221–239. 14. Hutchinson JN. Reading the ground: morphology and geology in site appraisal. Quarterly Journal of Engineering Geology and Hydrogeology 2001; 34:7–50. 15. Kruyt NP. Towards micro-mechanical constitutive relations for granular materials. Proceedings of Modern Approaches to Plasticity. Balkema: Rotterdam (The Netherlands), 1993; 147–178. 16. Calvetti F, Combe G, Lanier J. Experimental micromechanical analysis of a 2D granular material: relation between structure evolution and loading path. Mechanics of Cohesive-Frictional Materials 1997; 2:121–163. 17. Jiang MJ, Konrad JM, Leroueil S. An efficient technique for generating homogeneous specimens for DEM studies. Computers and Geotechnics 2003; 30:579–597. 18. Lanier J, Jean M. Experiments and numerical simulations with 2D disks assembly. Powder Technology 2000; 109:206–221.
URI:	http://wrap.warwick.ac.uk/id/eprint/40548

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