Rock burst which releasing large quantity energy

may damage the roadway severely and reduce the safety of the production of coal mine. Using similarity simulation experiment under explosive loading and the digital speckle correlation method(DSCM)

the dynamic failure process of roadway under high velocity impact loading is simulated. The results show that the impact wave is mainly in roadway direction and the deformation of the roof is obvious. At the same time

the roof has a cutting rupture and a displacement between coal body and upper roadway. The roof has a tension-shear rupture

and also the crack extends to roadway gradually. Roof broken or partial collapsing area appeared under the repeat impact loads. Digital speckle pattern observations show that the sinking displacement of roof about 4mm under impact load. And then the impact wave spreads to two sides of the roadway. The rock drops along the surface after broken. It assumes that the blank white space appears on the speckle patterns.