Composite viaducts on the Urban Highway “Siervo de la Nación”

The execution of the compoiste (steel&concrete) viaducts of the urban highway “Siervo de la Nación” between Mexico City and Ecatepec is progressing. IDEAM, S.A. has carried out the detailed design and the technical support for the construction company, Mota-Engil.
Viaduct 3 has two complex composite sections. The section between piers P15-P19 has been resolved by means of a continuous bridge of 127 m and 3 spans of 28 + 75 + 24 m, and the section between piers P36-P48 has been resolved by two continuous bridges with a length of 590 m , with variable spans between 38 m and 56 m.
The deck of both bridges, 19.15 m wide and a curved plan with a minimum radius of 312 m, has two strict box girders (4 webs), with a composite multi girder section in mid span and double composite action in hogging areas.
The seismic-resistant strategy of both viaducts has been based on an isolation-dissipation scheme using lead-core neoprene devices.
In Viaduct 2 there are a series of branches that connect the trunk of the V2 with the different roads on the other side of the Grand Canal. These are several composite isostatic bridges with box girder cross section and spans between 54 and 66 m.