Discrete Element Modeling of the Effect of Particle Shape on Creep Behavior of Rockfills

Authors: Yunjia Wang, Zhihong Zhao, Erxiang Song

Abstract:

Rockfills are widely used in civil engineering, such as dams, railways, and airport foundations in mountain areas. A significant long-term post-construction settlement may affect the serviceability or even the safety of rockfill infrastructures. The creep behavior of rockfills is influenced by a number of factors, such as particle size, strength and shape, water condition and stress level. However, the effect of particle shape on rockfill creep still remains poorly understood, which deserves a careful investigation. Particle-based discrete element method (DEM) was used to simulate the creep behavior of rockfills under different boundary conditions. Both angular and rounded particles were considered in this numerical study, in order to investigate the influence of particle shape. The preliminary results showed that angular particles experience more breakages and larger creep strains under one-dimensional compression than rounded particles. On the contrary, larger creep strains were observed in he rounded specimens in the direct shear test. The mechanism responsible for this difference is that the possibility of the existence of key particle in rounded particles is higher than that in angular particles. The above simulations demonstrate that the influence of particle shape on the creep behavior of rockfills can be simulated by DEM properly. The method of DEM simulation may facilitate our understanding of deformation properties of rockfill materials.

Keywords: Rockfills, creep behavior, particle crushing, discrete element method, boundary conditions.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1132286

References:

[1] Sowers, G. F., Williams, R. C., & Wallace, T. S. (1965, September). Compressibility of broken rock and the settlement of rockfills. In Proc. 6th ICSMFE (Vol. 2, pp. 561-565).
[2] Marsal, R. J., Arellano, L. R., Guzmán, M. A., & Adame, H. (1976). Infernillo: Behavior of dams built in Mexico. Instituto de Ingeniería, UNAM, Mexico.
[3] Oldecop, L. & Alonso, E. (2007). Theoretical investigation of the time-dependent behaviour of rockfill. Géotechnique 57, No. 3, 289–301.
[4] Cheng, Y. P., Nakata, Y., & Bolton, M. D. (2003). Discrete element simulation of crushable soil. Geotechnique, 53(7), 633-642.
[5] McDowell, G. R., & de Bono, J. P. (2013). On the micro mechanics of one-dimensional normal compression. Géotechnique, 63(11), 895.
[6] Tapias, M., Alonso, E. E., & Gili, J. (2015). A particle model for rockfill behaviour. Géotechnique, 65(12), 975-994.
[7] Alonso, E. E., Tapias, M., & Gili, J. (2012). Scale effects in rockfill behaviour. Géotechnique Letters, 2(3), 155-160.
[8] Tran, T. H., Vénier, R., & Cambou, B. (2009). Discrete modelling of rock-ageing in rockfill dams. Computers and Geotechnics, 36(1), 264-275.
[9] Potyondy, D. O. (2007). Simulating stress corrosion with a bonded-particle model for rock. International Journal of Rock Mechanics and Mining Sciences, 44(5), 677-691.
[10] Zhao, Z., & Song, E. X. (2015). Particle mechanics modeling of creep behavior of rockfill materials under dry and wet conditions. Computers and Geotechnics, 68, 137-146.
[11] Zhou, M., & Song, E. (2016). A random virtual crack DEM model for creep behavior of rockfill based on the subcritical crack propagation theory. Acta Geotechnica, 11(4), 827-847.
[12] Zhou, W., Ma, G., Chang, X., & Zhou, C. (2013). Influence of particle shape on behavior of rockfill using a three-dimensional deformable DEM. Journal of Engineering Mechanics, 139(12), 1868-1873.
[13] Potyondy, D. O., & Cundall, P. A. (2004). A bonded-particle model for rock. International journal of rock mechanics and mining sciences, 41(8), 1329-1364.
[14] Silvani, C., Désoyer, T., & Bonelli, S. (2009). Discrete modelling of time‐dependent rockfill behaviour. International journal for numerical and analytical methods in geomechanics, 33(5), 665-685.
[15] Kwok, C. Y., & Bolton, M. D. (2013). DEM simulations of soil creep due to particle crushing. Géotechnique, 63(16), 1365-1376.