岩石非线性破裂的衰减特征

THE ATTENUATION CHARACTERISTIC OF ROCK'S NON- LINEAR FRACTURE

在实验室内，模拟了在构造应力和引潮力的共同作用下岩石失稳破裂的过程，记录了整个过程中不同应力条件下通过岩石样品的纵波波形曲线．以此为基础，分别在时间域和频率域计算了Ｐ波波列能量随应力的变化；并根据Ｑ值的定义，导出了接收到的波列的能量与岩石衰减Ｑ的关系式，从而计算出不同应力条件下相应的Ｑ值及其变化．利用加卸载响应比的定义，得到以Ｑ为响应参数时岩石系统的加卸载响应比随应力的变化曲线，其结果和响应比理论的预测相当吻合．因此认为，Ｑ值的加卸载响应比可以表征岩石系统的稳定程度，并可以用于预测岩石的非线性失稳．

In the laboratory,rock samples were loaded to instability under the common action of simulated tectonophysical and tide forces,and the waves-form curves passed the rock in the whole process were recored. The P wave eneries under different pressure were calculated in the time range and frequency range. According to the difinition of Q, the relationship between Q value and energy was deduced. Then the Q values under different pressure were calculated and it's change was discovered. By using the definition of loading and unloading response ratio, the curve of response ratio about Q values was obtained,which was found to be finely agree with the theoretical prediction. We concluded that Q as a response ratio could indicate the stability degree, and was also a good precursor to predict the failure of the rock system.