UTE Line 9
Description of the Environmental Measure
In the tunnel for Line 9 of the Barcelona Underground, noise levels from the conveyor belt carrying excavated material , the rubble tip, the cranes and the conveyor line were higher than allowed by legislation and were potentially a signifi cant nuisance to nearby residents as work was being done around the clock.
Because the construction site was in an urban area, and considering the amount of noise being emitted, it was decided to erect a 60x10-metre metal structure with soundproof panels to reduce the acoustic impact of the conveyor belt and auxiliary machinery. A 4,000-m2 soundproof roof was also built over the TBM crossing shaft in the La Sagrera zone.
Installing acoustic panels brought the noise levels down considerably (by about 30 dB), as shown by the acoustic studies conducted periodically during execution.