裂隙充填影响巴西圆盘抗拉力学特性试验研究

裂隙是影响岩石力学特性和破裂模式最重要的因素之一，通过试验、数字照相技术和声发射监测对完整和含不同裂隙倾角 单裂隙、不同岩桥与裂隙夹角 双裂隙充填与非充填类岩石材料巴西圆盘的抗拉强度和破裂模式进行研究，探讨了随着 、 的不断变化和裂隙充填与否对试样最终破坏机制的影响。试验结果表明：（1）随着裂隙倾角 不断增大，单裂隙试样的抗拉强度先减小后增大，然后又减小；预制裂隙尖端萌生的翼裂纹贯通造成试样破坏；（2）双裂隙试样的抗拉强度随着 的增大先减小后增大；预制裂隙尖端萌生的翼裂纹和远场裂纹的扩展导致试样破坏；（3）在 、 相同的情况下，充填试样抗拉强度明显要高于非充填试样；预制裂隙充填与否对试样裂纹扩展的时间和裂纹数目影响较大；（4）加载初期，声发射较为平稳；宏观裂纹出现或者抗拉强度跌落时声发射将会变的异常活跃；在 、 相同的情况下充填试样声发射的起伏变化更为剧烈。

Experimental study of influence of crack filling on mechanical properties of Brazilian discs

Fissure is one of the most important factors affecting mechanical properties and failure modes of rocks. Based on experimental results, digital photographic technology and acoustic emission (AE) monitoring to investigate tensile strength and failure modes of intact, and containing different crack angles ? single, different angles between rock bridge and crack ? double filled and unfilled pre-existing fissures rock-like material Brazilian disc samples. The effects on final failure mechanisms of samples with the change of filling condition, ? and ? are also discussed. The results show that the tensile strength of single pre-existing fissure filled samples decreases firstly and then increases and finally decreases with the increase of ?. The wing cracks initiate from the tip of the pre-fissure, and then cut-through, finally the samples show brittle destruction. The tensile strength of those samples containing two pre-existing fissures decreases firstly and then increases with the increase of ?. The propagation and evolution of wing cracks initiated from two pre-existing fissures and far-field cracks lead to the the destruction of samples. The tensile strength of filled samples is higher than unfilled samples obviously, when the corresponding values of ? and ? are the same. Whether the pre-existing fissure filling has a great impact on the crack propagation time and the number of cracks. At the initial loading stage, the cumulative acoustic emission counts are relatively stable. When the surface of samples initiated cracks initially or the tensile strength increases to the peak, the acoustic emission activities become extremely active. When the corresponding values of ? and ? are the same, the fluctuation of acoustic emission counts of the filled samples is more violent than that of the unfilled.