Barge Bow Force–Deformation Relationships for Bridge Impact-Resistant Design: Development and Assessment Using Shock Spectrum Approximation

Abstract

Force–deformation relationships of waterway vessels play an important role in the impact-resistant design of bridge structures. Characterizations of barge bow force–deformation (i.e., crushing) behaviors found in design provisions and previous research are reviewed as part of the present study. Results obtained from use of the relationships in impact analyses are then compared with computed responses from high-resolution finite-element barge–bridge collision simulations. As motivated by the comparisons, new relationships are proposed to further enhance designer capabilities for head-on barge impact design. In developing the proposed relationships, a parametric study of nonlinear dynamic collision simulations is performed to account for impacted pier surface geometry and barge bow versus impacted surface widths. Considerations are also made for impact velocities and peaks in force magnitudes that can occur for deformations near to the onset of nonlinear bow crushing. Merits of the proposed force–deformation relationships are then assessed via the shock spectrum approximation method. Key characteristics of barge bow force–deformation relationships (e.g., initial stiffness, maximum force, residual force plateau, impulse) are identified across typical ranges of bridge vibration periods and also in relation to propensities of empirical curve components for bringing about severities in computed structural demands.