The Municipality of Rome in Italy has completed a 320 metre long, 1.4 metre diameter sewer bypass using microtunnelling under major roads and two sporting facilities including the Olympic stadium and Foro Italico in the central district of Farnesina.
Microtunnelling was chosen by authorities in order to minimise the size of the construction area, reducing disruptions in the densely populated area, particularly during regular sporting events.
Italian companies Safab Spa. and La Falce Spa. had been contracted to complete the works, which involved boring a tunnel in preparation for a slurry pipe, using a machine fitted with laser guidance control systems through different layers of soil, such as clay, sand and gravel between 6 metres and 15 metres a day.
The planned line consisted of 135 metre and 185 metre straights that connected at a 60 degree angle, with a manhole for access and inspection to the main jacking station. Two thrust shields had also been constructed to keep the relatively light tunnel boring machine in place, where it was simply rotated to the required position.
The project used Hobas CC-GRP jacking pipes with an external diameter of 1,499 mm, weighing 415 kilograms per metre.
Farnesina is situated on the right bank of the Tiber River, and is headquarters of the Italian Foreign Ministry, as well as the junction of the Cassia and the Flaminia roads.