Tunnel Construction

AIR provides the following codes for tunnel construction:

While Coverage C (content) is not supported for most of the 200-series construction class codes, it is, supported for Inland Transit (construction code 259) and for some other construction codes, such as tanks and pipelines. For the full list of supported combinations, refer to the "Const. & Occ. Combin." tab in each model supplement.

Construction Code	Category	Description
213	Alluvium Tunnels	Tunnels that were drilled through unconsolidated sedimentary deposits and then typically lined with concrete For exposures in South America, use 2131.
214	Rock Tunnels	Rock tunnels are lined or unlined tunnels that were drilled through rock. For exposures in South America, use 2141.
215	Cut and Cover Tunnels	Tunnels that were constructed by cutting a trench, installing a liner, and then covering the liner with earth
2131	Alluvium Tunnels	Lined or unlined alluvium tunnels with unknown method of construction Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.
2132	Alluvial Bored Tunnels	Lined or unlined tunnels constructed through alluvium soil using a boring machine Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.
2141	Rock Tunnels	Lined or unlined rock tunnels with unknown method of construction Valid for South America and Southeast Asia, Mainland China, and the United States.v
2142	Rock Bored Tunnels	Lined or unlined tunnels drilled through rock using a boring machine Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.
2150	Unknown Tunnel	Lined or unlined tunnels with unknown material and unknown method of construction, or other tunnels that cannot be mapped to any of the other tunnel construction class codes Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.
2151	Rock Cut and Cover Tunnels	Lined or unlined rock tunnels constructed after excavating a trench and roofing over with an overhead support system Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.
2152	Alluvial Cut and Cover Tunnels	Lined or unlined alluvium tunnels constructed after excavating a trench and roofing over with an overhead support system Valid for South America and Southeast Asia, Mainland China, and the United States. Also valid for AIR Earthquake Model for New Zealand.

Touchstone 7.0 Updated September 03, 2020