A Bonded Particle Model Simulation of Shear Strength and Asperity Degradation for Rough Rock Fractures
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Abstract
Different failure modes during fracture shearing have been introduced including normal dilation or sliding, asperity cut-off and degradation. Attempts have been made to study these mechanisms using analytical, experimental and numerical methods. However, the majority of the existing models simplify the problem, which leads to unrealistic results. With this in mind, the aim of this paper is to simulate the mechanical behaviour of synthetic and rock fracture profiles during direct shear tests by using the two-dimensional particle flow computer code PFC2D. Correlations between the simulated peak shear strength and the fracture roughness parameter D R1 recently proposed by Rasouli and Harrison (2010) are developed. Shear test simulations are carried out with PFC2D and the effects of the geometrical features as well as the model micro-properties on the fracture shear behaviour are studied. The shear strength and asperity degradation processes of synthetic profiles including triangular, sinusoidal and randomly generated profiles are analysed. Different failure modes including asperity sliding, cut-off, and asperity degradation are explicitly observed and compared with the available models. The D R1 parameter is applied to the analysis of synthetic and rock fracture profiles. Accordingly, correlations are developed between D R1 and the peak shear strength obtained from simulations and by using analytical solutions. The results are shown to be in good agreement with the basic understanding of rock fracture shear behaviour and asperity contact degradation.
Keywords
Fracture Shear strength PFC Roughness Asperity degradation Simulation DR1References
- Asadi MS (2011) Experimental and PFC2D numerical study of progressive shear behaviour of single rough rock fractures. PhD Thesis, Curtin University, PerthGoogle Scholar
- Asadi MS, Rasouli V (2010) Direct shear test simulation of real rough rock fractures, Eurock2010. Luasanne, ZwitzerlandGoogle Scholar
- Asadi MS, Rasouli V (2011) PFC2D simulation of directionality in rough fractures shear strength. In: 2nd International FLAC/DEM Symposium, Ist edn. Itasca Consulting Group, MelbourneGoogle Scholar
- Asadollahi P, Tonon F (2010) Degradation of rock fracture asperities in unloading, reloading, and reversal. Int J Numer Anal Methods Geomech 35(12):1334–13046CrossRefGoogle Scholar
- Bandis SC, Lumsden AC, Barton NR (1983) Fundamentals of rock joint deformation. Int J Rock Mech Min Sci Geomech Abstracts 20:249–268CrossRefGoogle Scholar
- Barton N (1973) Review of a new shear-strength criterion for rock joints. Eng Geol 7:287–332CrossRefGoogle Scholar
- Barton N, Choubey V (1977) The shear strength of rock joints in theory and practice. Rock Mech Rock Eng 10:1–54Google Scholar
- Belem T, Homand-Etienne F, Souley M (2000) Quantitative parameters for rock joint surface roughness. Rock Mech Rock Eng 33:217–242CrossRefGoogle Scholar
- Belem T, Souley M, Homand F (2007) Modeling surface roughness degradation of rock joint wall during monotonic and cyclic shearing. Acta Geotech 2:227–248CrossRefGoogle Scholar
- Bruno MS, Nelson RB (1991) Microstructural analysis of the inelastic behavior of sedimentary rock. Mech Mater 12:95–118CrossRefGoogle Scholar
- Cho N, Martin CD, Sego DC (2007) A clumped particle model for rock. Int J Rock Mech Min Sci 44:997–1010CrossRefGoogle Scholar
- Cho N, Martin CD, Sego DC (2008) Development of a shear zone in brittle rock subjected to direct shear. Int J Rock Mech Min Sci 45:1335–1346CrossRefGoogle Scholar
- Cundall PA (2000) Numerical experiments on rough joints in shear using a bonded particle model. In: Lehner FK, Urai JL (eds) Aspects of tectonic faulting. Springer, Berlin, pp 1–9Google Scholar
- Ferrero A, Migliazza M, Tebaldi G (2010) Development of a new experimental apparatus for the study of the mechanical behaviour of a rock discontinuity under monotonic and cyclic loads. Rock Mech Rock Eng 43:685–695CrossRefGoogle Scholar
- Giacomini A, Buzzi O, Krabbenhoft K (2008) Modeling the asperity degradation of a sheared rock joint using FEM. In: 8th World Congress on Computational Mechanics (WCCM8), Venice, ItalyGoogle Scholar
- Huang TH, Chang CS, Chao CY (2002) Experimental and mathematical modeling for fracture of rock joint with regular asperities. Eng Fract Mech 69:1977–1996CrossRefGoogle Scholar
- ISRM (1978) International society for rock mechanics commission on standardization of laboratory and field tests: suggested methods for the quantitative description of discontinuities in rock masses. Int J Rock Mech Min Sci Geomechan Abstracts 15:319–368CrossRefGoogle Scholar
- Itasca Consulting Group I (2008) PFC2D-particle flow code in two dimensions. Itasca Consulting Group I, MinnesotaGoogle Scholar
- Ivars DM, Potyondy DO, Pierce M, Cundall PA (2008) The smooth-joint contact model. In: 8th World Congress on Computational Mechanics (WCCM8); 5th European congress on computational methods in applied sciences and engineering (ECCOMAS 2008), Venice, ItalyGoogle Scholar
- Jing L, Stephansson O (2007) Fundamentals of discrete element methods for rock engineering: theory and applications. Elsevier, AmsterdamGoogle Scholar
- Karami A, Stead D (2008) Asperity degradation and damage in the direct shear test: a hybrid FEM/DEM approach. Rock Mech Rock Eng 41:229–266CrossRefGoogle Scholar
- Koyama T, Jing L (2007) Effects of model scale and particle size on micro-mechanical properties and failure processes of rocks–A particle mechanics approach. Eng Anal Boundary Elem 31:458–472CrossRefGoogle Scholar
- Lambert C, Buzzi O, Giacomini A (2010) Influence of calcium leaching on the mechanical behavior of a rock-mortar interface. A DEM Anal Comput Geotech 37:258–266CrossRefGoogle Scholar
- Lee HS, Park YJ, Cho TF, You KH (2001) Influence of asperity degradation on the mechanical behavior of rough rock joints under cyclic shear loading. Int J Rock Mech Min Sci 38:967–980CrossRefGoogle Scholar
- Park J-W, Song J-J (2009) Numerical simulation of a direct shear test on a rock joint using a bonded-particle model. Int J Rock Mech Min Sci 46:1315–1328Google Scholar
- Patton F (1966) Multiple modes of shear failure in rock. In: Proceedings of the 1st international congress on rock mechanics, vol 1. Lisbon, pp 509–13Google Scholar
- Piegl L, Tiller W (1997) The NURBS Book. Springer-Verlag, Berlin¸ HeidelbergCrossRefGoogle Scholar
- Plesha ME (1987) Eigenvalue estimation for dynamic contact problems. J Eng Mech 113:457–462CrossRefGoogle Scholar
- Potyondy DO, Cundall PA (2004) A bonded-particle model for rock. Int J Rock Mech Min Sci Geomech Abstracts 41:1329Google Scholar
- Rasouli V (2002) Application of Riemannian multivariate statistics to the analysis of rock fracture surface roughness. Imperial College of Science, Technology and Medicine, LondonGoogle Scholar
- Rasouli V, Harrison JP (2010) Assessment of rock fracture surface roughness using Riemannian statistics of linear profiles. Int J Rock Mech Min Sci 47:940–948CrossRefGoogle Scholar
- Saito H, Grasselli G, Ferrero A (2007) Accounting for local roughness in geostatistical simulation of fracture surface topography. Rock mechanics: meeting society’s challenges and demands. Taylor & Francis, Boca Raton, pp 167–175Google Scholar
- Wang C, Tannant DD, Lilly PA (2003) Numerical analysis of the stability of heavily jointed rock slopes using PFC2D. Int J Rock Mech Min Sci 40:415–424CrossRefGoogle Scholar
- Yang ZY, Chiang DY (2000) An experimental study on the progressive shear behavior of rock joints with tooth-shaped asperities. Int J Rock Mech Min Sci 37:1247–1259CrossRefGoogle Scholar
- Yoon J (2007) Application of experimental design and optimization to PFC model calibration in uniaxial compression simulation. Int J Rock Mech Min Sci 44:871–889CrossRefGoogle Scholar