ABSTRACT
With an overall length of approximately 27km, Valico Tunnel is the longest tunnel at present in Italy, and the main infrastructure along the new railway line “Terzo Valico dei Giovi”, running from Genoa to Tortona. The first 7.7 km-long stretch in the northern side is being excavated by means of two 9.77m-diameter EPB-TBMs, crossing various geological formations at the junction between the southern part of the western Alps and western termination of the northern Apennines. Values of overburden up to 420 meters, the complexity of geology and high groundwater pressures around the lining, are some of the geotechnical challenges expected during the excavation. Furthermore, the TBM are expected to run into geological formations containing asbestos fibers and methane gas, requiring particular procedures that affects logistic of the jobsite. Such conditions make this tunnel one of the most challenging and complex project currently under construction.
