Investigation of Prestressed Concrete Bridge Girders Under Overheight Vehicle Collisions

Prestressed concrete bridge girders (PCBG) are susceptible to damage when exposed to overheight vehicle collisions. This paper presents high-fidelity finite element models developed using LS-DYNA software. Thirteen models were validated against experimental data from the literature. The validated models were then implemented to perform a parametric study investigating the key factors affecting the dynamic response of PCBG under vehicle collisions, including vehicle speed and mass, girder span, and girder type. The response of each girder was quantified in terms of impact force time histories. The study revealed that relying solely on metrics such as peak impact force, kinetic energy, momentum, and impact speed is insufficient for accurate girder dynamic response representation. The collision time is a critical factor that needs to be incorporated. Thus, the most critical factor that can represent uniquely the dynamic response of prestressed girders is impact impulse. The results of this study can assist in the quantification of the dynamic demand and the development of design guidelines that will enhance the safety and resilience of prestressed bridge structures.