This study investigates the dynamic response and damage mechanisms of underground structures under explosive impacts. A 3D numerical simulation was conducted to analyze the coupled interaction among the explosive, rock mass, and a concrete circular-arch structure with straight walls. A dynamic explicit finite element model was developed and validated by comparing key physical quantities with those from previous model tests. Based on the validated model, systematic sensitivity analyses were performed to evaluate the effects of explosive charge mass, concrete strength, and reinforcing bar strength on structural dynamic responses. The research findings indicate that variations in energy dissipation pathways within underground structures, induced by different types of equivalent explosives, are the primary factors governing the damage characteristics of such structures. Under the test conditions of this model study, enhancing the concrete and reinforcing steel strength of underground structures can effectively mitigate overall structural deformation. However, solely increasing the strength grades of concrete and steel reinforcement exhibits a significantly diminishing marginal return in improving the blast-resistant performance of underground structures. The research findings elucidate the damage evolution mechanism of underground structures subjected to explosive shock loading, thereby offering theoretical support for optimizing anti-explosion design parameters in protective engineering.
Yang et al. (Wed,) studied this question.