High speed train line Milan – Bologna

published: 18 12 2006
The new railway linking Bologna to Milan is part of the High Speed Lines network at present under construction in Italy.

The new railway linking Bologna to Milan is part of the High Speed Lines network at present under construction in Italy.
It crosses the Po river near Piacenza in a section where the river is usually about 350 m wide, up to 1 km between the main embankments. The total bridge is 1200 m long, 400 m cable stayed to cross the ordinary riverbed, an obliquity of 22° resulting between the tracks and the river.
Four main spans of 96 m were proposed in the preliminary design to satisfy the navigation requirement, and two solutions, both with prestressed concrete decks, were selected after a first study, but the competent Authority for the Environment insisted in eliminating the central pier, a 192 m main span resulting for that.
Anyway, the new cable-stayed bridge over Po River in the railway line Milano - Bologna maybe considered the most representative structure of the new high-speed railway network in Italy.
As far as we know, it is the first cable-stayed bridge in the world for high-speed railway line designed to operate at a speed up to 300 km/h.
It has a 192 m central span and two 104 m side spans; the deck is a prestressed concrete (PC) continuous box girder with-the fixed point at one tower, sliding bearings at the second tower and at the transition piers.
Expansion lengths of 296 and 104m derived from this arrangement of the bearings, joints in the rails so being required. The height of the cross section is constant and equal to 4,5 m along the central span; it varies and decreases to 3,70 m in the side spans, in order to fit with the other approaching decks.
All the decks have been built by cantilever method with cast in situ segments.
The towers are 60 m high from the footing, 51 m from the deck, made of reinforced concrete for all length apart from the top, where the stays are anchored, that is a steel and concrete composite structure.
The foundation of each tower has the footing (shaped to reduce the drag force) supported by 28 piles, 2m diameter and 65m long.

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Project : High speed train line Milan – Bologna. Cable stayed bridge over the Po river
Location : Po river, Piacenza
Type : P.c. continuous box girder cable stayed deck
Total lenght of bridge
: 400 m.
Stayed span lenghts : main span 192 m. and lateral span 104 m each all stayed
Deck width : 15 m.
Height of towers from deck level : 60 m.
Stay cable strand
: 530 tons
No. of stays : 72
Longest stay cable : 105 m.
Max. no. of strands per anchorage : 91 x 15.7 mm. dia.
Main Client : TAV SpA
Contractor : ASG scarl
Designer : MPA – Mario Petrangeli e Associati
Period : 2003 - 2006