Roads & Motorways

A31 'Valdastico' motorway

Lot 16 and 17 flyover and underpass
Owner/client Serenissima Costruzioni S.p.A.
Type of service Construction Design
Location Provinces of Padova and Rovigo
Period 2006 - 2007
Cost € 13.400.000

The project involved shop drawings and assistance to the construction firm to build structures across the new stretch of A31 motorway from Vicenza to Rovigo, lots 16-17. The works shown in the shop drawings, subject to design optimization, are four three-span flyovers and six single-bore underpasses.

The design was refined by working together with all the subjects involved in building the works (architectural metalworkers, precasters for prestressed concrete bridge beams and supports, specialists in deep foundation construction, and manufacturers of support devices and joints). The aim of favouring the building firm's site operational requirements was achieved by adopting technologically advanced solutions which improved shop drawing standards.

Lot 16 - Flyover

Flyover C24: 3 spans (17+38+17 m); Flyover C25: 3 spans (17+38+17 m).

Lot 16 - Underpasses

S06: n°15 precast prestressed beams; bridge opening = 15.20m; width = 33.54m; S07: n°16 precast prestressed beams; bridge opening = 15.15m; width = 40.72m; S08: n°6 precast prestressed beams; bridge opening = 18.85m; width = 16.03m

Lot 17 - Flyover

Flyover C32: 3 spans (15+33.5+15 m); Flyover C34: 3 spans (35+33.5+15 m).

Lot 17 - Underpasses

S09: single bore; reinforced concrete cast in situ (9.50x4.00m); S10: n°13 precast prestressed beams; bridge opening = 20.46m, width = 33.70m; S11: n°13 precast prestressed beams; bridge opening = 20.46m, width = 33.70m.

Posa travi S08
Posa travi S08
Posa travi S09-S10
Cavalcavia C25
Cavalcavia C24
Cerniera base pile

In particular, the flyovers were built with continuous mixed steel/concrete beams over three spans: in compliance with the conditions in the shop drawings, the lower route was chosen, which allowed low approach embankments to be built. The shoulders were built with reinforced concrete structures (with limited height, which were either precast or cast in situ as laid down in the shop drawings). The supports include shock-transmitter type seismic devices as indicated in Italian Prime Minister's Ordinance No. 3274.

The underpasses are designed to maximize the use of precast components both for the decks (precast prestressed concrete beams) and the underlying structures (shoulders consisting of precast panels) in order to simplify the building firm's operational requirements.

The foundations of the flyover shoulders and underpasses were built with traditional large diameter drill or helical screw piles according to the nature of the ground. Considerable deep mixing consolidation or embankment draining works were entailed to counter short and long-term subsidence.

The objective of favoring the operational needs of the company for site activities has been achieved by adopting advanced and improved technological solutions compared to the standards of the Executive Project.