Suffolk County | USA


Excavation diameter

3.81 m


Tunnel length

4,328 m


Geology

Clay, silt, sand, gravel


Type of support

Prefabricated segments


Completed in

2022


Client

Suffolk County – Long Island (New York)


Underwater sewer tunnel in New York State made with cutting-edge techniques, freezing for the shafts and Slurry TBM for the tunnel.

In particular, soil freezing technology was used to stabilise the soil during the excavation of the shafts.

An innovative Slurry TBM was used for the excavation of the underwater tunnel, capable of advancing both with the pipe pusher system and by installing lining rings in prefabricated segments.

The sandy-clay nature of the formations required the installation of a sludge treatment plant enhanced with centrifuges and filter presses capable of separating even the finest portions of the soil.

The excavation was carried out during the most critical period of the COVID epidemic and required a special sacrifice from the workers in order to continue working despite the fact that infections often reduced worker numbers.

This project was awarded the prize for best infrastructure construction site in the US for 2021, in the category of projects under $500 million.

Other featured projects


Val Lemme | Italy


Radimero | Italy


Serravalle | Italy


Lonato | Italy


Suffolk County | USA


Tsuen Wan | Hong Kong


Poza Honda | Ecuador


Beles Tailrace | Ethiopia


Beles Headrace | Ethiopia


Kishanganga | India


El Alto | Panama


Xe-Pian Xe-Namnoy | Laos


CCD Grande Dixence | Switzerland


Vancouver Underground – Canada Line | Canada


Milan Underground Line 5 | Italy


Doha Underground – Gold Line | Qatar


Algiers Underground | Algeria


Abdalajis East | Spain


Railway to Jerusalem – Line C | Israel


Lodz Railway Tunnel | Poland


Los Bronces | Chile


Cairo Underground | Egypt


High Speed railway Messina – Catania | Italy


High Speed railway Fortezza-Ponte Gardena | Brennero