本文以顆粒流程式PFC3D(Particle Flow Code3D)模擬橫向等向性岩石在巴西試驗下之張力強度、破壞模態及裂隙發展過程，探討不同方位角(ψ)與加壓角(β)對岩石張力強度之影響。進行橫向等向性岩石模擬前，亦針對等向性岩石巴西試驗探討微觀參數、試體厚徑比、顆粒尺寸效應、加壓速率與原生異向性之影響，亦作為橫向等向性岩石參數之參考。 本文模擬具有不同方位角之橫向等向性岩石在承受不同加壓角之荷重作用下，其巴西張力強度與Dan et al., (2013)針對佛萊堡片麻岩(Freiberger Gneiss)所進行之試驗結果具定性上相似性，數值模擬結果顯示：方位角與加壓角皆會影響巴西張力強度，且方位角對巴西張力強度之影響較加壓角之影響顯著。不同方位角之橫向等向性岩石承受不同加壓角的荷重，其微裂隙發展遠較等向性岩石複雜。即使同一方位角的試體，在不同的切片處其破壞模態亦有所不同，可區分為七種破壞模態：（1）穿層破壞模態、（2）層間劈裂模態（3）、弱層劈裂模態、（4）層間滑動模態、（5）弱層滑動模態、（6）混合破壞模態及（7）壓碎破壞模態。 ;This study employs 3-D Particle Flow Code (PFC3D) to simulate transversely isotropic rock materials for differential orientation angle (ψ) and loading angle (β) that varies between "0°" to "90° " under Brazilian test. The majority of this study presents the results of the numerical simulation of the failure process, failure modes and tensile strength. Before simulating transversely isotropic rock, this study also carries out the parametric studies (including the analysis of micro-parameters, thickness diameter ratio, particle size effect, displacement rate and inherent anisotropy) of isotropic rock under Brazilian test. This study simulates different orientation angles of transversely isotropic rock with different loading angles, the numerical simulate results are similar to the result of Brazilian test (Freiberger Gneiss) by Dan et al., (2013). It has shown that the orientation angle and loading angle both will affect tensile strength, and the influence of orientation angle is much larger than the influence of loading angle. The failure procedure of transversely isotropic rocks is more complex than isotropic rocks, even the same specimen has different failure mode in different slices, we observe seven major failure mode: (1) Split across layer mode; (2) Split along layer mode; (3) Split along weak layer mode; (4) Sliding along layer mode; (5) Sliding along weak layer mode; (6) Mixed mode; (7) Crush mode.
