A constraint-based system for arranging bridge spans

Determining the span arrangement of a bridge that incorporates more than one construction method is time-consuming and tedious. This work develops an automatic, Constraint-Based Span Arrangement System for bridges (CBSAS), that generates economical span arrangements based on various constraints imposed by the user. The major constraints include (1) construction methods used, (2) allowable sections and economical lengths for the construction methods used, and (3) aesthetic factors between two adjacent spans and lengths constructed by different methods. CBSAS is built in a Windows based, object-oriented environment and allows the user interactively to specify constraints until a satisfactory span arrangement is obtained. CBSAS can serve as a useful tool for a designer in the preliminary bridge design phase.