Study on the damage mechanism of deep ingate lining structure disturbed by cyclic blasting

Abstract Frequent blasting disturbance is one of the important reasons for the damage of the deep ingate lining structure. Understanding the damage mechanism of the deep ingate lining structure under blasting disturbance field can help improve the design of blasting schemes and optimize the materials and forms of the lining structure. The article combined model experiments and numerical calculations to study the distribution characteristics, damage degree, and evolution law of the lining structure of deep ingate under cyclic blasting disturbance. The results showed that under certain confining pressure conditions, when the initial explosive charge exceeded the threshold, the arch crown, arch shoulder, and side walls of the same side junction section were damaged in sequence. After cyclic blasting disturbance, the cumulative damage values of these three parts were the highest. Secondly, the cumulative damage generated by the "first strong, then weak" disturbance on the same side as the first blasting was always higher than the "first weak, then strong" disturbance on the other side, and the cumulative damage value depended on the first damage value. When the blasting working face reached a safe distance, the damage no longer developed. Thirdly, after two cycles, the cumulative damage value of SFRC structure (DSFRC = 0.0043) was about 1/15 of that of HSC structure (DHSC = 0.032), indicating that SFRC exhibited superior anti explosion disturbance performance. The research results were of great significance for improving the safety of the deep ingate lining structure and reducing the impact of blasting disturbance.