A Knowledge‐Based System for Design of Bridge Trusses

Abstract

A knowledge‐based expert system, called BTEXPERT, has been developed for optimum design of bridge trusses by interfacing an interactive bridge truss optimization program with an expert system environment. The scope of BTEXPERT is limited to the optimum design of four types of bridge trusses, namely, Pratt, Parker, parallel‐chord K truss, and curved‐chord K truss for a span range of 100–500 ft. Design constraints and the moving loads acting on the bridge are based on the American Association of State Highway and Transportation Officials specifications. The structure and functions of various components of BTEXPERT are presented. Various focus control blocks, the building blocks of BTEXPERT, are described along with the relevant heuristic rules and procedures. The approach to expert systems used in BTEXPERT is novel in at least two respects. First, mathematical optimization is introduced in the expert system. Second, the knowledge base of BTEXPERT contains not only heuristic rules and experiential knowledge but also knowledge obtained through machine experimentation.