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.
Il est difficile pour ne pas dire impossible, de pousser loin la pratique sans la spéculation, & réciproquement de bien posséder la spéculation sans la pratique.
Denis Diderot, Encyclopédie, entry “Art”
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Notes
- 1.
“La longueur des liens pendants varie avec la hauteur que l’on veut donner à chaque travée de ferme. M. Town donne à la ferme une hauteur égale au dixième de l’ouverture à franchir” [1], p. 100.
- 2.
See table of measuring unit.
- 3.
The bridge was about 12 m long and was built by Sir John Mc Neill [7], p. 92.
- 4.
“Hence the larger the pieces are in proportion to the distance between them” [6].
- 5.
“The height of the trusses is to be proportioned to the width of the openings between the piers or abutments, and may be about one-tenth of the openings, when the piers are fifteen feet or more apart – a less span requiring about the same height, for the reasons before stated” [8], p. 159.
- 6.
“The nearer those braces are placed to each other, the more strength will the truss have” [8], p. 159.
- 7.
“Suppose, for an example, it were required to ascertain the strength of a bridge on this improvement, from experiments made with a model. In this construction, the truss-work is carried across from pier to pier, so that the road-way entirely across, shall be in a horizontal plane, and all the parts shall retain their own respective magnitudes throughout the structure. Now, let l represent the horizontal length of the model, from interior to exterior of the two piers, w is the weight, w the weight it will just sustain at its middle point B before it breaks. Let nl the length of a bridge actually constructed of the same material as the model, and all its dimensions similar: then, its weight will be n²w, and its resisting power to that of the model, as n² to 1, being = \( {\text{n}}^{2} \cdot ({\text{w}} + \frac{1}{2} \cdot w) \).
Hence:
\( {\text{n}}^{2} \cdot \left( {{\text{w}} + \frac{1}{2} \cdot w} \right) - \frac{1}{2} \cdot {\text{n}}^{2} \cdot w = {\text{n}}^{2} \cdot {\text{w}} - \frac{1}{2} \cdot {\text{n}}^{2} \cdot \left( {{\text{n}} - 1} \right) \cdot w \), the load which the bridge itself would bear at the middle point” [11], p. 11.
- 8.
“Any information as to the construction and terms for the right to build, may be had by addressing the patentee, at the city of New York, who will attend promptly to those letters only, which are postage paid. Terms for Patent right, one dollar per foot, for the length of the bridge, if applied for and paid before commencing; otherwise, two dollars per foot will be charged, as indemnity for the risk of bad construction, when erected without proper directions and authority, by which great injury is generally done to both parties—the right being at the same price with advice and directions, as without” [11], p. 14.
- 9.
Deck area is equal to 98.13 m2.
- 10.
“en second lieu, parce que le calcul est établi comme si les travées ne faisaient que porter sur les palées, tandis qu’elles y sont a peu près encastrées, et l’on sait que lorsque l’encastrement est complet, la résistance est doublée” [18], p. 376.
- 11.
“Ce système de contre-ventement, on doit le dire, ne serait pas suffisant pour une construction de longue durée; il conviendrait sans doute de diminuer l’intervalle de 3 m.60 en le réduisant à 3 m.00 ou 2 m.40, et de placer quelques contrevents horizontaux entre le deux cours de moises inférieurs” [20], p. 379.
- 12.
The deck area is equal to 43.50 × 2.50 = 108.75 m2.
- 13.
Avant de fixer définitivement l’équarrissage des moises et leur écartement dans les fermes, nous avons soumis au calcul les disposition de notre projet, pour savoir si elles offraient une résistance suffissante” [22], p. 307.
- 14.
“On voit que ce dernier moment n’est que les \( \frac{55}{100} \) du moment des résistences; ce qui nous a décidé à adopter aves toute sécurité les dimensions indiquées dans le calcul que nous venons de donner” [22], p. 308.
- 15.
“après six jours de service, nous avons constaté que les moises supérieure et inférieure n’étaient plus horizontales et avaient pris une flèche de 0 m.08 mesurée au milieu de la portée de 17 m 00: six semaines après, nous avons reconnu que cette flèche était doublée, et c’est alors que nous nous sommes décidé à ajouter cinq croix de Saint-André dans la milieu de chaque ferme pour augmenter la résistance et arrêter cette flexion” [22], p. 308.
- 16.
“Nous n’avions d’abord composé nos fermes qu’avec de simples croix de Saint-André, comme nous venons de l’exposer; mais depuis nous avions reconnu la nécessité, ainsi que nous le dirons plus loin, d’ajouter des croix de Saint-André intermédiares dans le milieu des fermes; elles sont disposée absolument comme les premères et au nombre de cinq dans chaque ferme” [22], pp. 304-305.
References
Annales des Ponts et Chaussées (1837) Canaux et chemin de fer americains. Carilian-Goeury, Paris. 2eme semestre, pp 1–105
Poussin GT (1834) Travaux d’améliorations intérieures projetés ou exécutés par le gouvernement général des États-Unis d’Amérique de 1824 à 1831. Anselin Libraire, Paris
Annales des Ponts et Chaussées (1839) Travaux publics de l’Amerique du nord. Carilian-Goeury, Paris. 2eme semestre, pp 141–226
Smeaton J (1760) Experimental Enquiry concerning the Natural Power of Water and Wind, London
Stevenson D (1838) Sketch of the civil engineering of North America. Holborn, London
United States Patent and Trademard Office (1820) Patent Nr. 3169X, 28 Jan 1820
Humber W (1870) A complete treatise on cast and wrought iron, including iron foundations in three parts: theoretical, practical and descriptive, 3rd edn. Lockwood and co., London
Silliman B (1821) The American journal of science (and Arts), vol III. Converse, New Haven, pp 158–166
Town I (1821) A description of Ithiel Town’s improvement in the construction of wood and iron bridges. Converse, New York
United States Patent and Trademark Office (1835) Patent Nr. 8743X, 3 April 1835
Town I (1839) A description of Ithiel Town’s improvement in the construction of wood and iron bridges. Hitchcock and Stafford, New York
National Intelligencer (1838) Gales & Seaton, Washington DC 5–11th Aug 1838
New York Weekly Express (1838) Towsed & Brooks, New York 4 Aug 1838
New Haven Daily Herald (1838) JC Gray, New Haven, Connecticut 19 Sept 1838
Richmond Whig and public advertiser (1838) Pleasant & Abbott, Richmond, Virginia 19 Sept 1838
Douglas H (1816) An essay on the principle and construction of military bridges, and the passage or rivers. John Murray, London
Fulton R (1796) A treatise on the improvement of canal navigation. Taylor, London
Annales des Ponts et Chaussées (1842) Sur deux ponts provisoires en charpente construits dans le système américain de M. Town. Carilian-Goeury, Paris 2eme semestre, pp 371–377
Navier CLMH (1826) Résumé des Leçons Donnés a L’École des Ponts et Chaussées sur l’Application de la Mécanique à L’Établissement des Construction et des Machines. Firmin Didot, Paris
Annales des Ponts et Chaussées (1842) Pont provisoire sur l’Azergues, route départementale n°7. Carilian-Goeury, Paris 2eme semestre, pp 377–382
Navier CLMH (1823) Rapport et Mémoire sur les Ponts Suspendus, Imprimerie Royale, Paris
Annales des Ponts et Chaussée (1841) Sur une travée en charpente construite au Vaudreuil, route royale de mantes à Rouen, dans le système des ponts américains de M. Town. Carilian-Goeury, Paris 1ere semestre, pp 303–309
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Tardini, C. (2014). The Application of Structural Mechanics to Wooden Bridge Design: First Attempts. In: Toward Structural Mechanics Through Wooden Bridges in France (1716-1841). SpringerBriefs in Applied Sciences and Technology(). Springer, Cham. https://doi.org/10.1007/978-3-319-00287-3_3
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