Abstract: The whole process of crack initiating, propagation and through of rock specimen with single crack at various preset inclination angles under single axial compression was simulated by use of extended distinct element method (EDEM) and the stress variation in crack spreading stages was investigated and explored and the mechanism of single crack spreading with various preset inclination angles was analyzed. The results show that with the increase of inclined angle α of preset crack, the crack—starting stress of new cracks and compressive strength of the specimen are in overall tendency of increasing and sharp change occurred when α=30°. The crack developed most rapidly when α=30° . When α=15°, 45°, 60°, 75°, the crack expanding speed reduced progressively in order. When α=15° and α=30° , the new crack started expanding from the two wings of tip end of the pre-existing crack. When α increased from 45° to 75° , the new crack expanded gradually toward vertical depth along bilateral sides of the pre-existing crack. α=45° is the inclined angle at the transition of the two different crack expanding patterns.

Key words: tunnel engineering, geotechnical engineering；extend distinct element method (EDEM), numerical simulation, rock material, single crack

摘要： 采用扩展离散元（EDEM）计算方法，模拟了单轴压缩下含不同预置倾角的单裂纹岩石试样的裂纹起裂、扩展和贯通过程，探讨了裂纹不同扩展阶段的应力变化，分析了不同预置倾角下单裂纹的扩展机制。研究表明：随着预置裂纹倾角α的增大，新裂纹的起裂应力和试样的抗压强度总体上呈增大趋势，但当α=30°时出现突变；α=30°时试样裂纹扩展最为迅速，α=15°，45°，60°，75°时的试样扩展速度依次减弱；当α=15°，30°时，新裂纹从预置裂纹尖端的两翼开始扩展，当α从45°增大到75°时，新裂纹的扩展逐渐向着预置裂纹两侧纵深发展，α=45°时为两种不同裂纹扩展模式的过渡倾角。

关键词: 隧道工程, 岩土工程, 扩展离散元（EDEM）, 数值模拟, 岩石材料, 单裂纹