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根据岩石加载破坏过程中应力-应变和波速-应变曲线所反映的的波速变化特征,研究了岩石声波传播速度与其加载变形过程的相关性。研究表明:岩石破裂前波速及特征参数随着变形破坏阶段变化会有显著改变,特别是应力水平到达70%~80%之后,当加载破坏过程中岩石的裂隙大量增加后波速参数出现突变。这是由于在膨胀点附近岩石中微裂隙迅速丛集式增长,改变了岩石内部的微观结构,导致岩石波速降低。伴随着波速降低,波速走时急剧增大,离散度增大;S波和P波的振幅减小,但其振幅比急剧增大;S波、P的波Q值也会出现突变。通过对岩石加载过程中的波速变化与应力-应变曲线之间的关联性分析,利用波速信息变化可以实现对岩石脆性破裂前兆的识别。
According to the characteristics of wave velocity changes reflected by stress-strain and wave velocity-strain curves during rock loading failure, the correlation between rock acoustic wave propagation velocity and its loading deformation process is studied. The results show that the wave velocity and characteristic parameters change significantly with the deformation and failure stages before rock failure. Especially when the stress level reaches 70% ~ 80%, the wave velocity parameters change suddenly when the rock fracture increases greatly during the loading failure. This is because the microcracks in the rock near the expansion point are rapidly clustered and change the microstructure inside the rock, resulting in the decrease of rock wave velocity. With the decrease of wave velocity, the velocity of wave velocity increases sharply and the dispersion degree increases. The amplitude of S wave and P wave decreases, but the amplitude ratio sharply increases. The wave Q values of S wave and P wave also change abruptly. Based on the analysis of the correlation between wave velocity and stress-strain curve during rock loading, the change of wave velocity information can be used to identify the precursor of brittle fracture in rock.