Vibrations from explosive, high energy hydraulic hammers and tunnel boring machines: experience in Italian Tunnels

In the last ten years the driving of tunnels in hightly urbinized ares has become a pressing necessity in Italy. In the Dipartimento Georisorse e Territorio of Politecnico di Torino good sets of vibration records are available, concerning tunneling near residential sites, both from blasting works and from mechanized driving methods. The data included in the latter set have been collected either from high energy hydraulic hammer or from TBM driving works. A direct comparison among these three kinds of tunneling techiniques. In relation to the vibrations induced in the surroundings, is give as a further contribution to guide design decisions. The peculiarities of the three types of produced vibrations are also presented and shortly analyzed together with some considerations about the different approaches that should be taken in each case, according to the Authors, with regard to the admitted levels.