Economic Proportions and Weights of Modern Highway Cantilever Bridges

During the last decade there has been quite a development in the construction of long-span cantilever highway bridges; and a number of such structures have been designed in the writer's office. As the computations have always been made and recorded systematically, it was practicable to obtain weights of steel per linear foot of structure for the various divisions of the metal, namely, trusses, floor system, lateral system, anchorages, and on piers; and with these, by some established empirical formulas of transition, it was feasible to pass from known weights per foot in any layout to the corresponding weights per foot in a different but somewhat similar layout, and, in that way, and by means of moment-area diagrams, to determine all the economic functions for this type of highway bridge.