|Function / usage:||
Metro tunnel / subway tunnel
Tunnel boring machine (TBM)
Drilling and blasting
|Other name(s):||West Hills MAX Tunnel|
|Built:||1993 - 1996|
Geographic Information & Related Structures
Portland, Multnomah County, Oregon, USA, North America
|Coordinates:||45° 30' 38.00" N 122° 43' 1.00" W|
|length||5 000 m|
|depth||24 - 91 m|
Construction begins at west portal of north tunnel.
Boring begins at east portal of north tunnel.
|29 December 1995||
North tunnels meet after 16 months or driving the tube.
South tunnel boring begins.
|15 August 1996||
South tunnels meet after only 4 months.
|12 September 1998||
The tunnel is placed into service.
Tunneling was hampered by unexpected loose layers of silt and gravel, and crumbling basalt which prevented the custom boring machine from working effectively.
Currently there is no information available about persons or companies having participated in this project.
Relevant Web Sites
There is no relevant literature listed in the database.