Structural Behavior of Barges in High-Energy Collisions against Bridge Piers

Abstract

The collision of barges against bridge piers is an extreme loading condition that usually governs the design of bridges that span navigable waterways. The magnitude and time variation of impact forces depend on several aspects, such as mass and speed of the barges, stiffness of the impacted structure, and structural behavior of the barge. The latter has a considerable influence, not only because it defines the maximum possible impact force but also because it defines the energy absorption capacity of the barge. The structural behavior of barges has been studied using scale models and numerical methods. However, the total deformation reached in these studies was limited to the size of the barge bow. Hence, there is uncertainty in the behavior for high-energy collisions, where deformations may well exceed this deformation range. This paper studies the structural behavior of barges using detailed nonlinear finite-element (FE) models. Load-deformation relationships are established on the basis of the model results for different shapes and sizes of impacted structures. These relationships can be applied in simplified dynamic analyses for design, considering the large deformations expected for high-energy impact scenarios. Simplified analysis methods for symmetrical and oblique flotilla impacts are presented and validated against full FE models.