Design and execution of civil works, trackworks, electric traction systems and yard signalling/interlocking (IS) systems for the doubling of the Firenze–Viareggio railway line, Pistoia–Montecatini Terme section.

Project objective

The contract concerns the railway section between the stations of Pistoia and Montecatini (stations excluded) and includes trackworks from km 0+520 to km 11+700.
The double-track section, approximately 12 km long, provides for the construction of the second track largely alongside the existing track, except for a section of approximately 2,550 m (“Serravalle variant”), for which a new alignment is foreseen for both tracks.
Along the section, numerous structures are present: bridges and viaducts for crossing the main and secondary watercourses and the flood expansion basins of the Ombrone River, as well as the underground crossing of the mountainous relief (the “Serravalle” tunnel between km 6+257 and km 7+928). The civil works for the tunnel were developed at Executive Design stage by IGEAS Engineering S.r.l.

Main works

Serravalle Tunnel
The new tunnel comprises two distinct natural tunnel sections separated by a wide intermediate section (intermediate window) of artificial tunnel, as well as two artificial tunnel sections at the ends.

Artificial tunnel – Pistoia side
Della lunghezza di circa 174 m, prevede lateralmente il ricorso a paratie di pali ø800 mm in c.a. per il sostegno degli scavi e una paratia tipo “berlinese” con micropali ø300 mm per il sostegno del fronte di attacco della galleria naturale.

Artificial tunnel – “window”
Approximately 156 m long, with anchored Ø800 mm reinforced-concrete bored pile walls.

Artificial tunnel – Montecatini side
Della lunghezza di circa 174 m, prevede unicamente paratie tipo “berlinese” tirantate costituite da micropali ø240 mm.

Natural tunnel
The two natural tunnel sections are approximately 1,080 m and 218 m long.
Based on the different geomorphological and lithological conditions and the expected geological–geomechanical framework along the alignment, the most appropriate pre-support / pre-consolidation measures were defined.