A New Design For Torsion Resistant Suspension Bridges

The proposed design for improving torsional stiffness of the Manhattan Bridge was developed by the author as an alternate to published plans for reducing the excessively high maintenance costs of the bridge. A preliminary simplified model incorporating the principal components of the proposed design was analyzed. The results indicated a decrease in torsional deflections approaching 90%. Finally, a rigorous check was made using the computer to analyze three dimensional models of two suspension bridges. The bridges were the same in overall dimension and member size, except that one was conventionally framed and the other contained elements of the authors designs. The result supported all of the conclusions drawn from the analysis of the simple model; in fact, torsional deflections diminished by more than 90%.