Experimental study of deep tunnel surrounding rock rockburst proneness with similarity material simulating method based on digital speckle correlation technique

Using equivalent material simulating experimental method,with the help of digital speckle correlation technique,the rock burst tendency of deep tunnel surrounding rock is studied.The regularities of rock burst and surrounding rock failure considering the strength of materials,excavation speed and support pattern are analyzed.The internal relations between rock burst and surrounding rock deformation and failure in deep tunnel are sought.The experiment results contrasted with the actual rock types of the granite,diorite,etc.which has higher strength of rockburst,the surrounding rock failure characteristics are similar.The higher surrounding rock strength is,the greater probability of rock burst is;in the high stress state and intact rocks the excavation speed has a greater impact on the rock burst;bolt-mesh support has some control function to the tunnel wall rock deformation;but also to some extent avoided rockburst.Supporting test result is in conformity with the field situation;with the higher support strength,the tunnel resistance increased,the overall distortion reduced,the surrounding rock stability improved.The experiment results will provide technical guidance and theoretical basis for the rational design and safe excavation of deep tunnels and have great significance,for innovating deep tunnel excavation and support technology.