Damage characteristics and space-time evolution law of rock similar material under uniaxial compression

In order to study the damage characteristics and space-time evolution law of rock similar material, using the self-developed YYW-Ⅱ strain controlled unconfined compression apparatus and the PCIE-8 acoustic emission (AE) monitoring system, the active procedure of AE events and change of stress and strain of rock similar material sample in the process of uniaxial compression were monitored, the damage model of rock similar material under the condition of uniaxial compression based on accumulative AE events was established, the stages of damage development of rock similar material in the process of uniaxial compression were further analyzed, and the process of space-time evolution of damage of rock similar material under the condition of uniaxial compression was studied.The results show that the AE events activities are roughly experienced three stages of small amount in the period of initial compression, stable growth in the period of elastic deformation, and dramatic growth in the period of plastic deformation and damage; the process of damage can be divided into three stages of initial damage, stable damage and accelerated damage; the process of space-time evolution of damages better reflects the damage characteristics.For instance, in the case of No.1 sample, the damages start to develop and focus at the bottom of the sample in the first place, then damages appear in the middle and upper of the sample and stably extend to the bottom and top of the sample, and then damages rapidly grow in the middle and upper of the sample and connect the damage zone at the bottom of the sample, then the damage of the sample happens eventually.The research result can provide certain reference to the study of damage evolution law of similar material model.