Riu Sec Bridge

On 08/07/2022, the steel deck forming the designed load-bearing structure of the footbridge adjacent to the existing prestressed concrete bridge over the Riu Sec was installed on site, within the works for the cycle and pedestrian connection between Badia del Vallès and the UAB. The project is promoted by the AMB and executed by BENJUMEA, with MOST ENGINYERS providing technical assistance in relation to geotechnical and structural works. The structure consists of a single-span, simply supported deck with a 30.70 m span, made as a trapezoidal box section 884 mm deep with a top width of 1,820 mm, and featuring a profile that replicates the curvature of the existing concrete footbridge. A variable-thickness concrete wearing surface will be cast on the steel deck to achieve a texture similar to the current footbridge and to adjust levels along the alignment to match the existing profile.

The deck was fabricated in the workshop, where the full span was assembled in one piece, leaving a number of openings to allow internal welding operations. The openings were subsequently closed, quality control tests were carried out, and the entire deck was painted. This methodology reduces construction risks and environmental impacts while maximising execution quality, as complex operations are performed under controlled workshop conditions. Before placing the footbridge in its final position, reinforced-concrete, micropile-supported abutments were constructed, incorporating steel plates to which the bridge bearings will be welded.

To position the footbridge on the abutments, a special transport operation will be required from the fabrication workshop to Badia. Lifting the 17.2-tonne footbridge will require a 220-tonne mobile crane. Once set on the abutments, the required height and alignment adjustments will be made using hydraulic jacks. The deck will already have the neoprene bearings welded in place, so on site the only welding required will be to the plates previously installed on the abutments. The next construction steps will be the installation of the longitudinal and transverse expansion joints and the handrail, followed by the placement of the concrete wearing surface on the steel footbridge.
With the achievement of this milestone on Friday, completion of the works is now closer, and the new cycle route will soon be opened to the public.

Details

Year 08/07/2022

Emplacement Riu Sec

Activity Geotechnical and structural engineering project