live load

A live load refers to the external forces acting on a structure, in addition to its own weight (dead load). For bridges, this primarily includes the weight of traffic such as cars, trucks, and trains. Engineers estimate probable traffic loads for design, as the maximum conceivable load is often too costly to engineer for, especially on longer spans. A dynamic load is a specific type of live load, such as a moving vehicle on a bridge. Floor load is another term for live load on a floor, typically calculated in pounds per square foot. Earthquake forces are also considered loads on structures, particularly high-rise buildings, and their design must account for seismic wave periods and structural ductility.12345