Loads

Bridge demolition analysis is like erection analysis in that both must consider the effects from dead, live, and environmental loading. Dead loads include all permanent components of the structure, such as primary and secondary load carrying members, decks and overlays, barriers, railings, and ancillary structures. Live loads include traffic, pedestrians, construction personnel, equipment, shielding, and all other transient loading that may be on the structure during the demolition process. In general, environmental loading is controlled by wind, especially as the structure is partially deconstructed, but loading such as ice, snow, and seismic events should be considered on a project-specific basis. Whereas modern bridge design is typically performed using load and resistance factor design, allowable stress design is often preferred for bridge demolition because unfactored loads are required for calculating deflections and determining pick weights and pick locations. During demolition, contractors have a wide variety of equipment at their disposal to aid in various removal methods.