The Application of Structural Mechanics to Wooden Bridge Design: First Attempts

Abstract

One of the distinctive elements of the École des Ponts et Chaussées is that it has always created an open-minded attitude to new and interesting activities outside France. In the early 19th century, great interest was directed towards new wooden bridges structural typologies that flourished in the United States. France is drawn by the rationalization of design as a consequence of the need for standardization of the American world leading to the definition of simple, versatile, repeatable patterns. In turn the basis of structural mechanics has been developed by the French experience. The result is the beginning of a new approach to design based on structural mechanics that needs to be further developed, investigated and examined. The earliest French application of Navier’s bending theory is permitted by the simplicity of the structural layout proposed and patented by Ithiel Town. Furthermore, the first applications of Navier’s bending theory to practice are relative to testing procedures mainly related to existing structures and not to the design of new ones. This is not surprising considering that the typical deductive logic of the scientific procedure leads directly to the formulation of criteria for existing structures and, only at a later stage, is adapted to design needs. During this time span, most of the considered wooden bridge structural typologies are temporary structures, sometimes built for the rapid restoration of damaged or demolished masonry structures.