[Case Study, September 2009] -- Farnesina is one of Rome's central quarters and is situated on the right bank of the Tiber River. With La Farnesina as headquarter of the Italian Foreign Ministry the area is home to the ancient Milvio Bridge (109 a.c.), two meaningful sports facilities, namely the Olympic stadium and the Foro Italico, but also the junction of the 2 most important roads: The Cassia and the Flaminia.
For wastewater disposal, the municipality of Rome designed a sewer bypass in Farnesina, which runs between two already established concrete DN 3500 collectors. Totaling a length of 320 m, the line was planned with a nominal diameter of 1400 mm.
SAFAB Spa., a renowned Italian contractor specialized in hydraulic applications was assigned for the job and worked in close cooperation with the company La Falce Spa., whose no-dig know-how is based on 50 years experience.
The tunnel was prepared with a slurry pipe and a so-called MTBM, a Microtunneling Boring Machine featuring a laser guidance control systems. Driving through different layers of soil, such as clay, sand and gravel, a daily advance of 6 to 15 m could be achieved.
The first stretch of 135 m was excavated with the thrust from the main station, whereas the longest stretch of 185 m had to be driven with an intermediate jacking station.