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Abstract The large geomechanical model test to investigate the failure mechanism of rockburst tunnel under the static and explosive loads was carried out with the static load simulating the initial stress field and TNT explosion simulating the rockburst. The applied vertical pressure was equal to the uniaxial compressive strength of the similar material with the coefficient of lateral pressure of 1/3. Three levels of explosive loads were applied respectively. Rockburst phenomenon occurred when the last explosive load applied. The tunnel rockburst hazard was found to be the results of the combined action of dynamic and static loads. Impact load and the existing static load were superposed suddenly，which caused the superposed force to increase significantly and to be greater than the bearing capacity of the wall rock，leading to the rock impact failure to occur. The deformation due to impact and the initial deformation due to the tunnel excavation were superposed when the impact loads applied suddenly，leading to the failure of tunnel walls when the superposition deformation was greater than allowed. The deformation and the failure areas of the surrounding rock were affected by the impact load and the initial stresses.
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Received: 31 March 2014
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2014, Vol. 33 
