Case history: in situ verification of the intrinsic characteristics of the acoustic barriers installed along a new high speed railway line

In September 2005 the new high speed railway line Torino-Novara, Italy, was under completion and the acoustic barriers just installed according to the specifications. The authors did here the in situ verification of the intrinsic characteristics of the noise reducing devices, an essential part of the specifications. It is the first European experience of this kind on a large construction workplace. The conditions were extremely demanding and the time scheduled for the task very short. The challenging task was successfully completed applying CEN/TS 1793-5 and requesting a specific logistic support. The paper reports the key points of this successful experience and shows some exemplary results. The values measured in situ are compared with the results obtained some years ago on products of the same kind. The comparison is in favour of the reliability of the measurement method and gives some indications on its reproducibility. It is concluded that the selected method is fully adequate to in situ verification and could be repeatedly applied to check the acoustic durability of noise reducing devices over time.