Dynamic load testing of a modular truss bridge using military vehicles

ABS T R A C T Determination of appropriate load factors ensures bridge assessments completed using limit states design are applicable for all potential loading scenarios. Extremely limited research has been completed to determine ac-curate Dynamic Load Allowance (DLA) values for military vehicle loading of bridges, specifically independent values for tracked and wheeled vehicle types. An experimental testing program was used to assess the dynamic load effects caused by these vehicle categories by subjecting a bridge to loading from multiple different vehicle types at different speeds, while controlling deck surface condition. It was found that tracked vehicles generated approximately half the dynamic bridge response of wheeled vehicles. Using this knowledge, tracked vehicle DLA value recommendations relevant for this bridge are made for use in the North Atlantic Treaty Organization (NATO) Military Load Classification (MLC) system, and in the Canadian Highway Bridge Design Code (CHBDC) and American Association of State Highway and Transportation Officials (AASHTO) bridge code. Further research in this area could lead to strategic increases in tracked vehicle mobility.