Study on statistical characteristics of the acoustic emission energy of the pre-cracked rock materials
In order to better understand the basic characteristics of rock mass structure and the phenomenon of compression failure,a se-ries of uniaxial compression tests were carried out on sandstone specimens using loading equipment,acoustic emission systems and high-speed cameras.The results show that the fracture process of sandstone samples is divided into three stages:the original micro-crack clo-sure、micro-crack nucleation and macroscopic crack propagation;the damage energy of intact and single-slit specimens follows the power law distribution,indicating that the damage is critical.The best index(r)for a single-slit sample is about 1.64,which is slightly lower than the best index for a complete sample;the fitted power law index of the sandstone specimen will change at different stages of the ex-periment and gradually stabilize.Based on histogram analysis and maximum likelihood method,the presence of test cracks may affect the statistical characteristics of damage energy.The crack dip angle has little effect on the optimal index,but has a certain effect on the frac-ture mode of the specimen.The study provides a new theoretical basis for the collapse prediction of engineering rock mass structure.
rock materialpre-crackAE acoustic emissionpower law distribution
万方数据
维普
