Knowledge-based system for bridge rail design

Bridge Rail EXpert System (BREXS) is an advisory system built to aid novice engineers in coping with bridge rail design and retrofit. Motivation for development of BREXS stems from a need to integrate domain expertise and knowledge from complementary disciplines. Development goals for this system are to incorporate bridge rail knowledge bases, bridge rail databases, existing analytical computer codes, and fuzzy logic decision-making capabilities. The development shell, NEXPERT OBJECT is used to build the knowledge bases. The integration of NEXPERT OBJECT and other supporting applications is carried out using calling-in integration schemes, in which the integration of BREXS focuses around a central control model. Knowledge bases categorized according to function are (1) rail selection, and (2) retrofit railing. A bridge railing database is customized for graphical display. Two algorithmic programs written in C and FORTRAN are used to check selected design parameters. The rail selection knowledge base provides a mechanism for choice of an optimum rail, based on a set of criteria. These criteria include adherence to standard specifications, structural adequacy, benefit/cost ratio, safety, bridge geometry, climate, geographic location, and aesthetics. The retrofit railing knowledge base is used to choose an optimum rail as well as determine the optimum attachment position for projects involving replacement of rails. In addition, written specifications and graphical attachment details for the selected rail are provided. Target computing equipment is an IBM-compatible microcomputer with graphics capabilities that is running Microsoft Windows 3.0 or later.