不同矿物成分花岗岩剪切声发射特性研究

Study on Shear Acoustic Emission Characteristics of Granite with Different Mineral Compositions

摘要: 本研究探讨了矿物成分对花岗岩剪切破坏过程中声发射特性的影响。研究选取了两种矿物成分不同的花岗岩样本，分析了其力学效应、声发射特性及裂纹扩展模式的差异。通过实验研究发现，矿物成分多的花岗岩表现出更为复杂的力学响应，具有较强的非线性和突发性破坏行为，而矿物成分少的岩石则呈现平稳、均匀的剪切行为。此外，矿物成分多的岩石在剪切过程中释放出更多的声发射能量和较高的振铃计数，表明其破坏过程更加频繁且复杂。矿物成分少的岩石则表现出较低的声发射强度和较少的局部破坏信号。在裂纹扩展方面，矿物成分丰富的岩石呈现复杂且快速的裂纹扩展模式，局部破坏频繁；而矿物成分少的岩石裂纹扩展则较为均匀，缺乏复杂的微裂纹交互作用。研究表明，矿物成分对岩石的微观结构、力学性质及破坏模式具有显著影响，矿物成分较多的岩石在剪切破坏过程中易出现突发的能量释放和裂纹扩展，因此在岩石力学性能预测和工程设计中，矿物成分可以作为评估岩石剪切行为和破坏机制的重要参数。

Abstract: This study investigates the effect of mineral composition on the acoustic emission (AE) characteristics during shear failure of granite. Two granite samples with different mineral compositions were selected to analyze their mechanical effects, acoustic emission characteristics, and crack propagation modes. Experimental results showed that granites with a higher mineral composition exhibited more complex mechanical responses, characterized by stronger nonlinearity and abrupt failure behavior, while those with fewer minerals demonstrated more stable and uniform shear behavior. Furthermore, granites with a higher mineral composition released more acoustic emission energy and higher ringing counts during shear, indicating a more frequent and complex failure process. In contrast, granites with fewer minerals exhibited lower acoustic emission intensity and fewer localized failure signals. Regarding crack propagation, rocks with a rich mineral composition displayed complex and rapid crack propagation modes, with frequent localized failures, whereas those with fewer minerals exhibited more uniform crack propagation, lacking complex micro-crack interactions. The study highlights that mineral composition significantly influences the microstructure, mechanical properties, and failure modes of rocks. Granites with a higher mineral composition are more prone to abrupt energy release and crack propagation during shear failure. Therefore, mineral composition can serve as an important parameter for evaluating rock shear behavior and failure mechanisms in rock mechanics performance prediction and engineering design.