Analysis and evaluation of dynamic stress ratio for tunnel roof's stability under production blasting

Blasting vibration field tests are performed on the tunnel roof under daily production blasting by Blastmate Ⅲ to investigate the effect of middle-deep hole explosion on the roofing stability. The result indicates that blasting amplitude and frequency gradually decrease with increasing distance between test point and explosion source. Dynamic stress ratio is applied to analyze the roofing stability based on analyzing the testing results. (DSR≤0.125). The results indicate that there is no roofing damage or breakdown under the same explosive conditions.