| dc.description.abstract | This paper employs 2-D Particle Flow Code (PFC2D) to simulate layered rocks and focuses on the tensile strength, failure process, and failure modes under Brazilian test. Besides, this paper presents the effect of layer thickness ratio and strength ratio on tensile strength and failure modes. Before simulating layered rocks, this paper also performs the parametric studies (including the sensitive analysis of micro-parameters, size effect, displacement rate, and inherent anisotropy) of isotropic rocks under Brazilian test. Based on the numerical simulation results, the inclination angle (θ), layer thickness ratio, and strength ratio all have significant effects on Brazilian tensile strength. The tensile strength of layered rocks decrease with the increase of inclination angle, and the tensile strength would increase with the increase of strength ratio. The tensile strength of layered rock would also increase with the increase of layer thickness ratio when the low inclination angle; however, there is no significant effect when the layered rock with high inclination angle. During Brazilian test, the micro-crack of layered rock initiate at pre-peak. Besides, the micro-cracks are limited around the edge of specimen and propagate slowly until the peak is reached. After post-peak, the crack propagate rapidly and we observe four major failure modes in these numerical simulations:(1)Split across layers mode;(2)Sliding along layer mode;(3)Mixed mode;(4)Split along layer mode. In this paper, we also verify our simulation result to experimental results from Cho et al.(2012). The strength anisotropy, elastic constants and failure modes almost agree with experimental results. | en_US |