Learning outcomes of the course unit
With the achievement of credits, the student will acquire the basic concepts and methods for the design of bridge structures, with particular reference to the identification of the resistant mechanisms, actions, methods of calculation, criteria for sizing the bridge deck structures, substructures and accessory equipment.
Fulfillment of the courses of mechanics of deformable bodies and structural mechanics. Basic knowledge from the courses of reinforced and prestressed concrete structures, steel structures, masonry structures.
Course contents summary
Generalities, general design concept, historical review, location of the bridge, environmental impact.
Actions on bridges, influence lines, calculations.
Beam bridges, metallic trusses, box girder bridges in steel and prestressed concrete, steel and concrete hybrid systems
Definitions and nomenclature relating to bridges. The placement of the bridge with respect to the watercourse; Notes on the calculation of regurgitation. The longitudinal section of the bridge; the free gabarit; the height of construction. Straight and oblique crossings. Introduction to mobile bridges. The evolution of construction technique for bridges. The materials used in the construction of bridges. Location of urban and suburban bridges. Verification of the environmental impact.
The technical standards for road bridges. External actions.
The calculation of stresses due to moving loads. Theory of influence lines. Design and calculation of bridge deck slabs.
Prestressed concrete girder bridges. Transverse distribution of loads in parallel beam decks. The calculation of the transversal beams. Torsion-rigid box girder bridges. Continuous beams, Gerber beams, beams with counterweights. The launch of the prefabricated beams. The cantilevered bridges.
Constraints. Supports. Joints. The substructure of bridges: shoulders, pillars, foundations. Introduction to railway bridges. Typical decks of railway bridges. Main trusses. Bracing beams.
The arched bridges. Two hinged arches: determination of the thrust. Hypothesis of Rèsal-Sensini. The decay of the thrust. Stress influence lines. Intersection curve. Effect of temperature variations and foundation settling. The frame-arch bridge. Bowstring arches. The Langer bridge. The calculation of fixed arches. Influence lines.
Masonry bridges. The method by Méry. The bridges of the type "Risorgimento" and "Africa". The "Maillart" bridges. The "Melan"system. Introduction to cable-stayed bridges. Nonlinear response. Effective stiffness of cables: the Ernst modulus.
Testing of the bridges.
The computational methods and the specific technologies of construction for bridges will be discussed. In addition, each student will design some parts of a bridge.
Suggested text books
G. Albenga, I ponti, Voll. I e II, Ed. UTET, Torino, 1953.
E. Siviero, Il progetto del ponte, Ed. Coll. Ingg. Prov. Padova, Padova, 1994 - M.P. Petrangeli, Progettazione e costruzione di ponti, IV ed., Ed. Masson, Milano, 1997.
F.Martinez, Ponti e viadotti: concezione, progetto, analisi, gestione, Ed. Pitagora,
Autori vari, Nuovi orientamenti per la progettazione di ponti e viadotti, Ed. Dario Flaccovio, Palermo, 2005.
A. Raithel, Costruzione di Ponti, Liguori, Napoli, 1983.
C. Menn, Prestressed Concrete Bridges, Springer Verlag, Wien, 1986.
J. Schlaich, H. Scheer - Concrete box girder bridges – IABSE AIPC IVBH – 1982.
R. Walther, Cable Stayed Bridges, 2nd edition, Thomas Telford, London, 2003.
Lectures possibly accompanied by. Numerical examples of application in the classroom. Revisions of plans. Technical visits.
Assessment methods and criteria
Final oral examination.
The oral examination will verify if the student has what lessons learned in specific applications