A knowledge based approach to preliminary highway bridge design

Abstract

This study examines the preliminary design of several types of highway bridges using a knowledge based approach. There are many different types of highway bridges and the ability to choose the best type of structure and a reasonable starting point for the design spiral comes from many years of experience. Preliminary design is often difficult for less experienced engineers because it involves using past experience and general "rules of thumb" to make decisions about initial engineering details. This study focuses on the development of a knowledged based system which would help to guide the inexperienced engineer to a preliminary design configuration for highway bridges. The knowledge based system developed in this study focuses on the preliminary design of four different types of highway bridges used in the state of Texas, slab span, panform span, precast I-beam span, and steel plate girder span. The preliminary design model takes, as input, several initial design parameters from the user, selects the best structure type, and develops an initial design configuration using periodic input from the user. The engineering details for the preliminary configuration can then be shown in spreadsheet format. The simulations contained in this study show that practical design problems can be approached from a knowledge based standpoint.