Bridges presentation
in compression on the bottom edge and a maximum value in tension on the top with a neutral axis
somewhere between the two surfaces. The problem of understanding bending moments in
mechanical terms was described by Louis Marie Henri Navier in his Résumé de leçons données à
l'École des Ponts et Chaussées in 1826. The Swiss mathematician Leonard Euler provided the
solution to the elastic buckling of columns as early as 1759.
Railroad viaducts and trestles
Railroads, the transportation mode that revolutionized the 19th century, generated a bridge type that
merits special attention. The limited traction of locomotives forced the railroad engineer to design
the line with easy gradients. Viaducts and trestles were the engineering solution for maintaining a
nearly straight and horizontal line where the depth and width of the valley or gorge rendered
embankments impracticable
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