Formation mechanism and engineering prediction of internal explosion damage patterns in concrete layered structure under small equivalent charges

To study the formation mechanism of the damage patterns of concrete runways under small equivalent charge conditions, the internal explosion damage effects of runways under different charge weights and detonation depths were investigated. By analyzing the evolution of damage forms such as cracks and heaves in the runway under the coupling effect of shock waves and gas products, the formation conditions of runway internal explosion damage patterns based on the radius of crack zone were proposed, and the formation mechanism of internal explosion damage pattern was clarified. The research results show that under different explosive effects, the impact loads generated by the explosive will produce crack zones of varying extents in each structural layer of the runway. The extent of the crack zones determines the loading area and loading mode of gas products on each structural layer, resulting in differences in the working process of gas products on each structural layer, and ultimately causing runways to form different internal explosion damage patterns. Based on the simulation results and the formation conditions of internal explosion damage pattern, a runway internal explosion damage pattern prediction model was constructed using the dimensional analysis method, and it has been verified to provide acceptable engineering precision within the scope of this study. The research findings provide technical support for the power evaluation and engineering application of small equivalent charges against concrete layered medium targets.