"Mali vrh" tunnel noise measurements (AC A2 tunnel Karavanke - Obrežje, 0020/0620 Malence – Šmarje sap)
In the context of active noise protection on the highway section from Malence to Šmarje Sap noise barriers were built and absorbing coating was put on all four portals of the Mali vrh tunnel.
As part of the noise barrier, different acoustic materials (cement-bonded-wood, aluminium, acrylic) were used. Noise barriers from cement-bonded-wood are grounded with bored concrete piles, while the aluminium noise barrier is laterally screwed to the AB high retaining wall. Polyacrylic transparent noise barriers are placed through the Reber viaduct.
To determine the effectiveness of the noise protection implementation in the Mali vrh tunnel, before and after the implementation of the restoration, a 24-hour measurements of acoustic emission and immission of noise at both tunnel portals, as well as in the nearby residential area, were carried out.
Measurements of reverberation time before and after the implementation of absorption lining in the Mali vrh tunnel have been carried out, as well as the in-situ acoustic measurements of the constructed noise barriers and testing of lateral load of concrete piles.