透明脆性材料预制裂纹压缩破坏机制试验研究

自然界中的岩体含有大量的原生裂纹,这些裂纹在外载作用下扩展和相互贯通最终导致岩体失稳破坏。由于真实岩石为不透明材料,观察研究其原生裂纹的扩展演化机制十分困难。最新研制了一种新型材料;该材料透明度高,且具有很好的脆性和单轴压缩剪涨性,可以作为模拟岩石的相似材料,在该材料内部及表面预制裂纹,观察分析预制裂纹不同赋存方式对材料破坏机制的影响。试验中清晰观察到次生裂纹萌生扩展各个阶段的形状及预制裂纹不同的赋存方式对材料破坏模式的影响,以及表面预制裂纹赋存深度与试件强度和次生裂纹裂最终扩展宽度的关系。试验所得的成果对于研究真实岩体的破坏机制具有重要的参考价值。

Progressive failure study on pre-existing crack of transparent brittle material

Engineering rock mass in the nature contains lots of primary cracks, the crack will propagation and coalescence until cause the engineering rock instability failure under the external loads. Because the initial and propagation process of cracks in real rock cannot be directly observed under external loads, the author developed a transparent rock-like material. This material is transparent and the fragility and dilatancy under uniaxial compressive is very good, so the new material can as similar material to simulation the real rock. Through pre-made cracks in the material interior and surface, observed and analysis the material failure mechanism under different existence modus of pre-existing cracks. the whole process of internal crack initiation and gradual propagation with the increase of load until form the macroscopic fracture surface which lead to the specimen damage can be clearly observed in the test. The influence of distribution ways of the pre-existing to the failure mode of the material and the relation between the depth of the surface cracks and the specimen strength and the final broadness of the secondary crack also can be observed in the test. The test research results provided an important reference value to research the failure mechanism of real rock .