Abstract
Block in matrix rocks (bimrocks) are known as a challenging material for engineering geologists due to their complex composition and associated difficulties in the determination of their mechanical properties. A novel numerical approach has been developed for the simulation of unwelded bimrocks based on the discrete element method. Three different types of contacts, including matrix–matrix, matrix-block and block-block, were assigned to the particles to mimic the mechanical behaviour of unwelded bimrocks. To investigate the validity of numerical models, the uniaxial compression and direct shear tests under different normal stresses were simulated and their results were compared with the physical experiments (glass bead blocks cemented by matrix plaster). The numerical uniaxial compressive strength (UCS) and direct shear tests at low volumetric block proportion (VBP) were found to be in good agreement with the experimental data, while they diverged with an increase in both VBP and the applied normal stress. It was found that an increase in VBP can lead to a decrease in both UCS and cohesive strength while the frictional strength increases. Also, it was concluded that an increase in the failed block-matrix contacts can lead to a decrease in the cohesion and UCS. At the same time, the occlusion effect of blocks can increase the internal friction angle. Detailed analysis on cracking mechanism showed that the increase in VBP results in a decrease in both crack initiation and damage stresses. Sensitivity analysis on micro-parameters showed that the tensile strength of block-matrix contacts is the most effective parameter on the strength.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Alidaryan M, Khosravi MH, Bahaaddini M, Moosavi M, Roshan H (2023) Mobilization of cohesion and friction angle of intact rocks in the shearing process rock mechanics and rock engineering.https://doi.org/10.1007/s00603-023-03484-z
Afifipour M, Moarefvand P (2014a) Mechanical behavior of bimrocks having high rock block proportion. Int J Rock Mech Min Sci 65:40–48. https://doi.org/10.1016/j.ijrmms.2013.11.008
Afifipour M, Moarefvand P (2014b) Failure patterns of geomaterials with block-in-matrix texture: experimental and numerical evaluation. Arab J Geosci 7:2781–2792. https://doi.org/10.1007/s12517-013-0907-4
Akram MS (2011). Physical and numerical investigation of conglomeratic rocks. PhD Thesis, School of Mining Engineering, University of New South Wales, Sydney, Australia
Akram MS, Sharrock GB (2010) Physical and numerical investigation of a cemented granular assembly of steel spheres. Int J Numer Anal Meth Geomech 34:1896–1934. https://doi.org/10.1002/nag.885
Altinsoy H (2006). A physical based model investigation for determination of shear strength of block in matrix rocks. MSc Thesis, Geological Engineering Department, Hacettepe University, Ankara, Turkey
Avşar E (2020) Contribution of fractal dimension theory into the uniaxial compressive strength prediction of a volcanic welded bimrock. Bull Eng Geol Environ 79:3605–3619. https://doi.org/10.1007/s10064-020-01778-y
Avşar E (2021) An experimental investigation of shear strength behavior of a welded bimrock by meso-scale direct shear tests. Eng Geol 294:106321. https://doi.org/10.1016/j.enggeo.2021.106321
Bahaaddini M (2017) Effect of boundary condition on the shear behaviour of rock joints in the direct shear test rock mechanics and rock engineering. 50:1141-1155https://doi.org/10.1007/s00603-016-1157-z
Bahaaddini M, Rahimi M (2018) Distinct element modelling of the mechanical behaviour of intact rocks using Voronoi tessellation model. Int J Min Geo-Eng 52:61–68. https://doi.org/10.22059/ijmge.2017.240741.594694
Bahaaddini M, Sharrock G, Hebblewhite B, Mitra R (2012). Direct shear tests to model the shear behaviour of rock joints by PFC2D. Paper presented at the 46th U.S. Rock Mechanics/Geomechanics Symposium, Chicago, IL, USA (24–27 June, Paper Number: ARMA-2012-457)
Bahaaddini M, Sheikhpourkhani AM, Mansouri H (2021) Flat-joint model to reproduce the mechanical behaviour of intact rocks. Eur J Environ Civil Eng 25:1427–1448. https://doi.org/10.1080/19648189.2019.1579759
Chang CS, Hicher PY (2005) An elasto-plastic model for granular materials with microstructural consideration. Int J Solids Struct 42:4258–4277. https://doi.org/10.1016/j.ijsolstr.2004.09.021
Coli N, Berry P, Boldini D, Bruno R (2009) In situ large size non conventional shear tests for the mechanical characterization of a bimrock in the Santa Barbara open pit mine (Italy). Paper presented at the 43rd U.S. Rock Mechanics Symposium & 4th U.S. Canada Rock Mechanics Symposium, Asheville, North Carolina (Paper Number: ARMA-09-184)
Cundall PA, Hart RD (1992) Numerical modelling of discontinua. Eng Comput 9:101–113. https://doi.org/10.1108/eb023851
Gao W, Iqbal J, Hu R (2021) Investigation of geomechanical characterization and size effect of soil-rock mixture: a case study. Bull Eng Geol Environ 80:6263–6274. https://doi.org/10.1007/s10064-021-02289-0
Goodman RE, Ahlgren CS (2000) Evaluating safety of concrete gravity dam on weak rock: Scott dam. J Geotech Geoenviron Eng 126:429–442. https://doi.org/10.1061/(ASCE)1090-0241(2000)126:5(429)
Graziani A, Rossini C, Rotonda T (2012) Characterization and DEM modeling of shear zones at a large dam foundation. Int J Geomech 12:648–664. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000220
Hovland HJ, Medley EW, Volpe RL, Goodman RE, Ahlgren CS (2001) Evaluating safety of concrete gravity dam on weak rck: Scott dam. J Geotech Geoenviron Eng 127:900–903. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:10(900)
Itasca Consulting Group i (2017) PFC (Particle Flow Code in 2 and 3 dimensions), version 5.0 User’s manual. Minneapolis, Minnesota
Jiang M, Yu H-S, Leroueil S (2007) A simple and efficient approach to capturing bonding effect in naturally microstructured sands by discrete element method. Int J Numer Meth Eng 69:1158–1193. https://doi.org/10.1002/nme.1804
Kahraman S, Alber M (2006) Estimating unconfined compressive strength and elastic modulus of a fault breccia mixture of weak blocks and strong matrix. Int J Rock Mech Min Sci 43:1277–1287. https://doi.org/10.1016/j.ijrmms.2006.03.017
Kahraman S, Alber M, Fener M, Gunaydin O (2008) Evaluating the geomechanical properties of Misis fault breccia (Turkey). Int J Rock Mech Min Sci 45:1469–1479. https://doi.org/10.1016/j.ijrmms.2008.02.010
Kalender A, Sonmez H, Medley E, Tunusluoglu C, Kasapoglu KE (2014) An approach to predicting the overall strengths of unwelded bimrocks and bimsoils. Eng Geol 183:65–79. https://doi.org/10.1016/j.enggeo.2014.10.007
Kruggel-Emden H, Wirtz S, Scherer V (2008) A study on tangential force laws applicable to the discrete element method (DEM) for materials with viscoelastic or plastic behavior. Chem Eng Sci 63:1523–1541. https://doi.org/10.1016/j.ces.2007.11.025
Liang Y, Cao L, Liu J, Sui W (2019) Numerical simulation of mechanical response of glacial tills under biaxial compression with the DEM. Bull Eng Geol Environ 78:1575–1588. https://doi.org/10.1007/s10064-018-1229-2
Lin Y, Peng L, Lei M, Wang X, Cao C (2019) Predicting the mechanical properties of bimrocks with high Rock block proportions based on resonance testing technology and damage theory. Appl Sci 9:3537
Lindquist ES (1994). The strength and deformation properties of melange. PhD Thesis, University of California, Berkeley, USA
Lindquist ES, Goodman RE (1994) Strength and deformation properties of a physical model melange. Paper presented at the 1st North American Rock Mechanics Symposium, Austin, Texas, June 1994, Paper Number: ARMA-1994-0843
Mahdevari S, Moarefvand P (2018) Experimental investigation of fractal dimension effect on deformation modulus of an artificial bimrock. Bull Eng Geol Environ 77:1729–1737. https://doi.org/10.1007/s10064-017-1074-8
Mahdevari S, Moarefvand P, Mohammadzamani D (2020) Considering the effect of block-to-matrix strength ratio on geomechanical parameters of bimrocks. Geotech Geol Eng 38:4501–4520. https://doi.org/10.1007/s10706-020-01304-7
Medley E, Goodman RE (1994) Estimating the block volumetric proportions of melanges and similar block-in-matrix rocks (bimrocks). Paper presented at the 1st North American Rock Mechanics Symposium, Austin, Texas, June 1994, Paper Number: ARMA-1994-0851
Medley EW (1994). Engineering characterization of mélanges and similar block-in-matrix rocks. PhD Thesis, University of California, Berkeley
Mohammadi HR, Mansouri H, Bahaaddini M, Jalalifar H (2017) Investigation into the effect of fault properties on wave transmission. Int J Numer Anal Meth Geomech 41:1741–1757. https://doi.org/10.1002/nag.2698
Napoli ML, Barbero M, Scavia C (2021) Effects of block shape and inclination on the stability of melange bimrocks. Bull Eng Geol Environ 80:7457–7466. https://doi.org/10.1007/s10064-021-02419-8
Oh J, Bahaaddini M, Sharifzadeh M, Chen Z (2019) Evaluation of air blast parameters in block cave mining using particle flow code. Int J Min, Reclam Environ 33:87–101. https://doi.org/10.1080/17480930.2017.1342064
Potyondy DO (2012) A flat-jointed bonded-particle material for hard rock. Paper presented at the 46th U.S. Rock Mechanics / Geomechanics Symposium, Chicago, USA, June 2012, Paper Number: ARMA-2012-501
Potyondy DO (2015) The bonded-particle model as a tool for rock mechanics research and application: current trends and future directions. Geosyst Eng 18:1–28. https://doi.org/10.1080/12269328.2014.998346
Rabiei-Vaziri M, Tavakoli H, Bahaaddini M (2022a) 2D numerical study of the mechanical behaviour of non-persistent jointed rock masses under uniaxial and biaxial compression tests. Geomech Eng 28:117–133. https://doi.org/10.12989/GAE.2022.28.2.117
Rabiei-Vaziri M, Tavakoli H, Bahaaddini M (2022b) Statistical analysis on the mechanical behaviour of non-persistent jointed rock masses using combined DEM and DFN. Bull Eng Geol Environ 81:177. https://doi.org/10.1007/s10064-022-02674-3
Riedmüller G, Brosch FJ, Klima K, Medley E (2001) Engineering geological characterization of brittle faults and classification of fault rocks. Felsbau 19:13–19
Roadifer JW, Forrest MP, Lindquist ES (2009) Evaluation of shear strength of melange foundation at Calaveras Dam. Paper presented at the Proc U.S. Society for Dams, Annual Meeting and Conference, 29th, on Managing Our Water Retention Systems, Nashville, Tennessee, p. 507– 521
Shi C, Bai J (2015) Compositional effects and mechanical parametric analysis of outwash deposits based on the randomised generation of stone blocks. Adv Mater Sci Eng 2015:863915. https://doi.org/10.1155/2015/863915
Sonmez H, Ercanoglu M, Kalender A, Dagdelenler G, Tunusluoglu C (2016) Predicting uniaxial compressive strength and deformation modulus of volcanic bimrock considering engineering dimension. Int J Rock Mech Min Sci 86:91–103. https://doi.org/10.1016/j.ijrmms.2016.03.022
Sonmez H, Gokceoglu C, Medley EW, Tuncay E, Nefeslioglu HA (2006) Estimating the uniaxial compressive strength of a volcanic bimrock. Int J Rock Mech Min Sci 43:554–561. https://doi.org/10.1016/j.ijrmms.2005.09.014
Sonmez H, Gokceoglu C, Tuncay E, Nefeslioglu HA (2004) Relationship between volumetric block proportion and overall UCS of a volcanic bimrock [J]. Felsbau: Rock Soil Eng 22(5):27–34
Yao Y, Li J, Ni J, Liang C, Zhang A (2022) Effects of gravel content and shape on shear behaviour of soil-rock mixture: experiment and DEM modelling. Comput Geotech 141:104476. https://doi.org/10.1016/j.compgeo.2021.104476
Yazdani A (2016). Modeling shear strength of block-in-matrix rocks (Bimrocks) using synthetic rock. MSc Thesis, Shahid Bahonar University of Kerman, Kerman, Iran (in Persian)
Zhang H, Boldini D, Wang L et al (2022) Influence of block form on the shear behaviour of soft soil–rock mixtures by 3D block modelling approaches. Rock Mech Rock Eng 55:3279–3300. https://doi.org/10.1007/s00603-022-02795-x
Zhang H, Hu X, Wang L et al (2023) Effect mechanism of block convexity on the shear behaviors of soil-rock mixtures by the developed 3D spherical harmonics based modeling approach. Comput Geotech 155(3):105183
Zhao Y, Liu Z (2019) Numerical experiments on triaxial compression strength of soil-rock mixture. Adv Civil Eng 2019:8763569. https://doi.org/10.1155/2019/8763569
Acknowledgements
The authors would like to acknowledge Mr. Amir Yazdani, Dr. Saeed Karimi Nasab, and Dr. Hossein Jalalifar for kindly providing the results of their physical experiments as well as their invaluable comments.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing interests.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Sheikhpourkhani, A., Bahaaddini, M., Oh, J. et al. Numerical study of the mechanical behaviour of unwelded block in matrix rocks under direct shearing. Bull Eng Geol Environ 83, 22 (2024). https://doi.org/10.1007/s10064-023-03507-7
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s10064-023-03507-7