DEVELOPMENT OF COST-EFFECTIVE BRIDGE SYSTEMS, PHASE II. FINAL REPORT

The goals of this study were, first, to provide the bridge designer with the concept of a systematic procedure that would enable him to select the most cost-effective short-span bridge superstructure for a prospective site, and second, to develop an optimization method that would provide him with the minimum-cost configuration of either a composite or a noncomposite bridge that is composed of a cast-in-place concrete deck on steel beams. To meet the first goal, a list was compiled of the bridge systems that have proven to be economical for span lengths of up to 100 ft. Decision logic tables were devised to help the designer select, from this list, a few of the more suitable bridge systems for a given site. An assessment procedure was established to rank the systems that survived the first level of screening. The bridge system with the highest ranking would be selected for the given site. An interactive computer program has been written for an IBM PC for implementation of the method. In order to reach the second goal, the elements involved in the design of the two selected bridge systems and their relevant design constraints were identified. Constraints were handled directly and the univariate search method of optimization was used. An interactive computer program was written in FORTRAN V that runs on the Conversational Monitor System of IBM. It provides the user with the necessary data for the minimum-cost configuration of either of the two bridge types.