A Study on Dynamic Response of Tunnel Blasting Using Numerical Simulation and Finite Element Analysis Software

The dynamic response characteristics of tunnel during blasting excavation are related to the safety of adjacent structures. Taking Yangjia Tunnel blasting underneath a five-story frame structure residential building as an example, the propagation law of blasting seismic wave was analyzed by HHT method through field blasting monitoring. Subsequently, the ALE algorithm in the finite element analysis software ANSYS/LS-DYNA was used to establish the simulation model of surrounding rock–cutting section–structure coupling to study the dynamic response of adjacent buildings under tunnel blasting vibration. The results show that HHT analysis method can clearly describe the energy distribution of vibration signals in time-frequency domain. The energy carried by blasting vibration signal corresponds to the initiation section, and the maximum energy appears in the cutting section, which further verifies that the vibration effect caused by cutting hole blasting is the strongest. In the process of tunnel blasting, there are obvious differences in the dynamic response of beams, columns and external walls near buildings, especially in the dynamic response law along the height direction. In addition, the stress concentration phenomenon has obvious specific distribution areas, including non-load-bearing parts such as the ground wall, which are more vulnerable to damage.