Expert System Applications for Bridge Engineering

Expert systems (ES) are computer programs that attempt to simulate the reasoning processes and knowledge of a human expert. The particular problem of bridge analysis/design is a prime candidate for ES development because many of the parameters of the problem, including bridge geometry, continuity, and material and member properties, are formulated using heuristic or 'expert' knowledge. This paper describes the development and application of an ES called KYBAS, an acronym for Kentucky Bridge Analysis System. KYBAS is actually a framework of interacting expert systems for assistance in structural analysis and design of highway bridges. The KYBAS framework ties a set of fundamental and necessary structural analysis algorithms coded in FORTRAN together with an expert system and related interfacing modules coded in C, resulting in a heterogeneous code. The ES knowledge base includes both factual and heuristic knowledge. The factual knowledge includes requirements set forth in the American Association of State Highway and Transportation Officials Specifications as well as certain finite element restrictions. Some of these restrictions apply to element type, aspect ratio, warping, and location. The heuristic knowledge includes rules for recommending bridge type, girder spacing, barrier type, diaphragm locations, etc.