To study the blast resistance of reinforced concrete (RC) bridge piers when subjected to explosive loads,this study conducted an field test on a three-span simply supported bridge featuring circular-section double-column piers.The analysis focused on the failure characteristics,damage level,and dynamic response of the double-column piers with circular-section subjected to both in-contact and non-contact explosive loads.The findings indicate that the failure mode of the bridge piers might shift from a local shearing failure mode to a bending failure mode due to variations in explosive equivalent and structural dimensions.Nevertheless,the extent of rupture in transversal and vertical directions is found to be dependent on the sectional stiffness in the corresponding directions,entailing local compressive and inclined shear cracks.In addition,the reinforcement shape after yielding at the location of rupture deviate from those observed in conventional bending failure.Compared to contact explosions,non-contact explosions result in significantly less damage at the equivalent of explosive mass due to the faster dissipation of energy.The diffraction effect of the shockwave,which is attributed to the large dimensions of the bridge columns and their large energy consumption capacities in the blast-facing surface,can be neglected in the anti-blast analysis of pier bodies. However,the confinement effect in the space beneath the bridge and the reflection of the ground and embankment must be taken into account in the analysis.For simplified design and analysis,double-column piers can be modeled longitudinally as pin supports at the top with two fixed ends when conducting transversal analysis.