Abstract: To deepen the understanding of damage processes and mechanisms of concrete gravity dams under near-field explosion loads, expressions for principal strain fields near crack tips and damage variables were derived based on the elastoplastic constitutive model of concrete and damage mechanics, and a theoretical analytical model for dam damage zones under near-field explosion loads was established. Experimental tests and numerical simulations were conducted to investigate dam fracture under downstream near-field explosion loads. The similarity between the boundaries of damage surfaces and fracture paths was quantitatively analyzed using a curve similarity algorithm, thereby validating the accuracy of the theoretical formulation for damage surfaces. Results indicate that during large-scale fracture of concrete dams under explosion loads, the initiation points of fracture paths in the residual dam structure are typically located in the transition zone outside the crushed zone. The fracture mechanism in this process predominantly aligns with mixed-mode I-II fracture (i.e., a combined tensile and shear-opening mode). The damage zone boundaries exhibit strong consistency with the fracture paths, confirming the reliability of the proposed model.