In a three-span bridge the theoretical advantage of continuity is about 49% for a dead load and 16% for a live load.
The four cables support a dead load of 7140 tons and a live load of 4017 tons.
(3) The dead load comprises the weight of the main girders, flooring and wind bracing, or the total weight of the superstructure exclusive of any part directly carried by the piers.
Dead Load.-The dead load consists of the weight of main girders, flooring and wind-bracing.
The weight of main girders increases with the span, and there is for any type of bridge a limiting span beyond which the dead load stresses exceed the assigned limit of working stress.