Study on the Dynamic Response Characteristics of Lining Structures in Large-section Tunnel Blasting Using JH-2 Model Analysis

Abstract

Abstract The lining structures of tunnels are typically constructed using sprayed or cast concrete materials, and their performance and quality during tunnel excavation and blasting are crucial for the stability and safety of tunnels. Therefore, the safe distance between the lining structure and blasting source should be determined to avoid concrete damage caused by blasting vibrations. In this study, using the Danshan large-section underground station tunnel in Qingdao as an example, the Johnson–Holmquist-2 (JH-2) model parameters of the local surrounding rock were obtained experimentally. Using numerical simulations and theoretical validation of the JH-2 model, this research focused on the safe distance for the lining structure concrete under various safety criteria. The results indicate that the JH-2 model can effectively simulate the propagation of stress waves under different media conditions, and the closer the strength parameters and pressure constant of the lining structure are to those of the surrounding rock, the safer the concrete–roc-k bonding interface. During tunnel blasting construction using the ring blasting method, the peak particle velocity (PPV) of the lining structure increases with an increase in the arch angle. Based on the numerical simulation results, we recommend that concrete lining be constructed at a distance of at least 62 m from the blasting source to avoid damage caused by vibrations. The effect of concrete tensile failure caused by longitudinal stress is much smaller than the damage to the bonding interface caused by the PPV and can be neglected.