Q. Write a short note on Economic Span of a Bridge?
The span for which the total cost of bridge will be minimum is known as the economic span.
The ratio of Cost of super structure and Cost of Sub structure = 1
Economical Span = √P / a ,
Where - a = p / l2 , p = Cost of pier ( Super structure ) , l = Span,
P = Cost of Pier ( Sub Structure ) , a = Constant of variation.