Lateral Load Distribution Factors for Military Vehicles on Multi-Girder Bridges

摘要

In general, military vehicles are heavier, wider, and have much different axle/tire configurations than 'civilian' type trucks for which conventional load distribution factors have been developed. Thus, use of conventional load distribution factors to rate bridges for military deployments often results in inaccurate ratings and thus unnecessarily limits mobility options for the military or threatens the safety of military personnel. This report provides an overview of an extensive study conducted to develop lateral load distribution factors specifically for military vehicles. The study considered six different types of military vehicles, three of which were wheeled vehicles and the other three were tracked vehicles. Formulas were developed for three different types of bridges: steel girder bridges, prestressed concrete bridges, and concrete T-beam bridges. The study resulted in a total of 52 new formulas for different categories of military vehicles, different types of bridges, bending moment and shear force values, interior and exterior girders, and for single- and multiple-lane loading cases. The distribution factors calculated with the formulas were compared with those calculated by direct analyses of the bridges to evaluate the accuracy of the proposed formulas.