Projects: Roads & Motorways

A31 'Valdastico' motorway


Lot 16 and 17 flyover and underpass

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.

  • Customer:Serenissima Costruzioni S.p.A.
  • Location:Provinces of Padova and Rovigo
  • Type of service:For Construction Design
  • Period:2006 - 2007
  • Cost:€ 13.400.000

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.

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.