Effect of Particle Shape on Mechanical Behaviors of Rocks: A Numerical Study Using Clumped Particle Model

• Published in: TheScientificWorld Vol. 2013; no. 2013; pp. 1 - 12
• Main Authors: Zhou, Chuang-bing, Hou, Di, Liu, Guang, Rong, Guan
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Publishing Corporation 2013; Hindawi Limited; Hindawi; Wiley
• Subjects: Atoms & subatomic particles; Computer simulation; Crack initiation; ENVIRONMENTAL SCIENCES; Geology; Geophysical research; GEOSCIENCES; Internal friction; Mechanics; Minerals - chemistry; Models, Theoretical; Modulus of elasticity; Particle shape; Plastic deformation; Poisson Distribution; Poisson's ratio; Research Article; Rock mechanics; Rocks; Sand & gravel; Sandstone; Shape; Shape effects; Studies; Triaxial compression tests
• ISSN: 2356-6140; 1537-744X; 1537-744X
• DOI: 10.1155/2013/589215

Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.