Vulnerability assessment of steel bridges due to on-deck blasts

Justus Frenz, University of Rhode Island


Highway bridges are a critical element in the infrastructure for personal transportation and movement of goods, yet they are constantly exposed to a number of impacts and risks. One of these possible threats is an accidental or intentional explosion on top of the bridge deck. ^ In this thesis, the effects of deterioration (in the form of section loss) of the superstructure subjected to a blast load are analyzed for an example bridge. The software ABAQUS and its CONWEP model were utilized to run a different scenarios of section thicknesses reductions of the steel elements, varying thicknesses of the concrete slab deck and the locations of the blast source. ^ The analysis output suggests that, for the blast load assumed in this thesis, only small parts of the concrete deck structurally fail while the rest of the bridge remains intact but permanently deformed in a way that a replacement of the bridge superstructure after the explosion appears to be inevitable. Increasing section loss obviously does have an impact on the deformations. However, the differences to the initial bridge structure observed in the analysis are only minor as the zones of structural failure and permanent deformations grow slightly but the overall stability does not change fundamentally. So, even though the initial bridge performs better when exposed to a blast event, initial and deteriorated bridges sustain permanent deformations making bridge replacement necessary in both cases.^

Subject Area

Civil engineering

Recommended Citation

Justus Frenz, "Vulnerability assessment of steel bridges due to on-deck blasts" (2016). Dissertations and Master's Theses (Campus Access). Paper AAI10142761.