Viaduct over the Osormort river

Name and location
Viaduct over the Osormort river near the town of Sant Sadurní d’Osormort (Barcelona, Spain)
Splitting of the road “Eix Transversal de Catalunya C-25”. Section: Gurb – Espinelves


Key features

Length: 500.1m
Spans: (31.7m + 11×39.7m + 31.7m).
Average height: 25m
Use: Road bridge
Materials: Reinforced concrete piers and abutments and prestressed concrete deck.
Construction: span by span method with self launched gantry

Property
CEDINSA dealership.

Construction
COPISA, CONSTRUCTORA PIRENAICA S.A.
Years: 2009-2010

BT Intervention
COPISA, CONSTRUCTORA PIRENAICA S.A.

General information
Drawings
Construction pictures

General information

The viaduct over the Osormort river, of 500.1m in length, is the longest in the road “Eix Transversal de Catalunya C-25”between Vic and Girona. It Crosses over two streams in an area of outstanding natural beauty and highly visible bycitizens.

The static scheme is the classical in road bridges of this size and spans:
– The deck is a prestressed concrete continuous hollow slab bridge with side cantilevers, 1.60m constant depth.
– The deck is supported on reinforced concrete piers and abutments.Neoprene bearings in central piers and longitudinal free pot bearings in extreme piers and inboth abutments

It is noteworthy that the viaduct is located in an area of moderate seismic activity, with basic soil acceleration a = 0.06g, this action hasbeing decisive in the design of many elements of the substructure.

All piers have direct foundation on footings, except the P1 pier, where must be used 10 piles of 850 mm diameter in order to avoid that theexcavation affected the BV-520 road service.

Theawarded project proposedto build the deck usingthe span by span method on falsework resting on the ground, but the constructor asked Bridge Technologiesto redesign the deck in order to buildit by means of a self launching gantry

All processes of bars reinforcement were standardized. The steel rods were pre-assembled at ground level in a workshop, where prestressing ducts were also positioned. The preassembled reinforcement was hoisted in sections up to the gantry with the help of an accessory structure designed for this purpose. After placing, passive bars were overlapping and the position of prestressing corrected

For the design of the slender piers, a geometric nonlinear and mechanical analysis was performed in order to better assess the second order effects

Drawings

Viaduct over the Osormort river 1

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Viaduct over the Osormort river 2

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Viaduct over the Osormort river 3

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Viaduct over the Osormort river 4

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Construction pictures