The high speed railway line connecting Barcelona and the French border crosses the Municipality of Vilafant 6 m below the ground level. To cross the sunken railroad, two pedestrian bridges have been planned. The structure, with one span of 46 m, is monolithically connected with the abutments. The use of unusual geometric shapes fabricated using stainless-steel and GFRP are blended in an innovative fashion, giving rise to an austere and elegant solution.
The two bridges have a main longitudinal span of 45,2 m and a deck width of 4 m. The structures are built-in on both abutments. The two bridges have a 4.3 m wide clear deck with a cross section consisting of two outwardly inclined hybrid trusses. An innovative structural hybrid truss has been designed. The combination of a stainless steel Vierendeel truss configuration with GFRP panels between vertical members creates an efficient, continuous structural web.
The geometry of the truss follows the structural demands from the integral frame configuration, having a variable height between 3.4 m at the abutment and 1.2 m at mid-span. The deck is built using slim GFRP ribbed panel planks over the transverse floor beams.
Two different floor beams are alternated every 1.02 meters: I-GFRP 300x150x15 mm for lightness and Stainless Steel rectangular 350×300 mm beams for rigidity. The GFRP panels between vertical elements in the Vierendeel trusses consist of a sandwich of two ribbed elements glued together for a total of an 80 mm thick translucent wall. The GFRP panels are continuously connected to both chords with stainless-steel bolts.
The structural innovation provided is a direct benefit of the R+D program where modeling and laboratory testing were performed by Pedelta in collaboration with the Institute of Building Sciences Eduardo Torroja (IETcc). In order to test the structural behavior and strength capacity of GFRP panels used as shear elements in hybrid truss configurations, several test models were designed.