Abstract: To systematically elucidate the ultimate bearing capacity of prestressed concrete T-girder bridges under typical blast scenarios, this study adopts an integrated approach combining experimental tests and numerical simulations. The research focuses on a full-scale (1:1) prestressed concrete T-girder bridge specimen as the test subject. A series of well-designed field blast tests were carried out to simulate various blast loading conditions. Subsequently, multi-stage static loading tests were performed on the blast-damaged specimen to quantitatively evaluate its residual structural bearing capacity and failure evolution process./t/nThe experimental program generated critical data, including detailed structural damage modes and corresponding deflection responses under both dynamic blast loads and subsequent static loads. Based on this experimental data, a high-fidelity three-dimensional finite element (FE) model of the prestressed concrete T-girder bridge was established and rigorously calibrated. This refined numerical model accurately incorporates material nonlinearity, prestressing effects, strain-rate sensitivity of concrete and reinforcement, and complex contact behaviors. The validated FE model was utilized as the primary tool for detailed quantitative analysis of the ultimate bearing capacity and failure mechanisms of the bridge under the considered blast loads./t/nThe key findings of this research are summarized as follows: (1) Under direct contact blast on the bridge deck, the dominant failure mode is localized perforation of the deck slab, accompanied by significant plastic deformation in the immediate vicinity of the blast center. For blasts occurring in the air gap between the main girders, the structural damage is more extensive. In addition to concrete scabbing and fragmentation on the soffit of the deck slab, the webs of the T-girders and cross-beams exhibit significant outward bending, along with severe concrete crushing or collapse. (2) Among the three typical blast-induced damage states analyzed, the most severe degradation in ultimate bearing capacity is observed under the combined damage scenario: an initial blast at the center of the bridge deck followed by a secondary blast between the girders. This damage sequence induces synergistic effects that significantly weaken the primary load-bearing components. (3) Strategically arranging the live load position on the blast-damaged bridge can effectively bypass the most severely damaged zones, thereby mitigating the adverse effects of blast-induced damage. Such load path optimization can achieve a substantial recovery or enhancement of the usable ultimate bearing capacity of the structure./t/nThis research provides a comprehensive methodology and valuable insights for the performance assessment of blast-damaged prestressed concrete bridges. The findings offer a solid theoretical basis and practical technical support for engineers tasked with evaluating the residual ultimate capacity of such structures and designing effective blast-resistant reinforcement or retrofit strategies.