The damage degree and acoustic emission characteristics of coal sample are closely related to coal-rock dynamic destabilization. According to destructive test of large size coal sample from Huating coal mine, the damage and acoustic emission test of large size coal samples with stratification structure of parallel and vertical are completed. The coal-rock failure process and damage degree are described by the using of state vector, which can forecast the catastrophic and rupture. Based on the analysis of related index of state vector, the damage degree of percentage is defined, which quantitatively reflects the local damage and rupture intensity of rock mass. This has theory and practice significance for the prediction of large scale mining out area instability and derivative disasters in strong earthquake zone.
In Western of china, the mining area of Huating, Ning Dong and Shizuishan belong to the strong earthquake area, a large range of dynamic instability have occurred in the mining process, which is a serious challenge to the safety of coal mining in western mining area. Damage and fracture of Non uniform medium is a challenging problem in mechanics, such as the damage evolution does not follow the steady accumulation in the stage of destruction and disaster, the traditional uniform theory of continuum mechanics is difficult to deal with (Bai et al. 2006). The phenomenon of emission occurs in the deformation process for the brittle materials such as coal and rock (acoustic, emission, AE), so the AE technology can be used for monitoring internal damage of material under loading (Lavrov 2003, Rudajev et al. 2000). As the coal damage and deformation has the inner relativity with the dynamic instability, the analysis of acoustic emission characteristics in the process of damage and deformation has been paid much attention to forecasting dynamic disasters. In addition, the law and mechanism of temporal and spatial distribution for coal medium collapse mostly are analysed by using numerical simulation, theoretical analysis and the uniaxial compression tests of coal sample with small size on the assumption of uniform medium (Xu et al. 2004, Wang et al. 2003), which has made pioneering advances.
