Underground construction

In the late 20th and early 21st century advances in automation and geotechnical engineering have allowed the ambition and scale of underground construction projects to increase.

[5][6] Archeology in major cities often requires the use of underground construction techniques as excavations must be made without disturbing existing buildings on the site.

Underground construction workers often work under reduced light condition, in dangerous spaces, and are at a high risk of exposure to contaminants, fire, and explosions.

In the United States the Occupational Safety and Health Administration (OSHA) first adopted unique regulations for underground construction in 1971.

Modern underground military facilities (primarily designed to resist aerial attack) emerged during the second world war and pre-war period.