Underground construction


Underground construction refers to the construction of underground tunnels, shafts, chambers, and passageways, it is also sometimes used to describe the portion of traditional construction that takes place below grade.

History

Underground construction likely began with cave dwelling pre-historic humans who wanted to expand their home. All ancient civilizations practiced some form of underground construction with some also branching into rock-cut architecture. In early urban centers underground spaces served as burial places, provided protection against invaders, and enabled early public utilities. The first known use of gunpowder in underground construction occurred in France in 1681. The invention of dynamite and steam and compressed air powered drills in the 18th century revolutionized the industry. The 19th century saw innovations in shield tunneling techniques which made underground construction in soil safer. As nations urbanized the extent of underground urban construction increased significantly with improved sewers, public water systems, subways, and underground commercial spaces all being required by expanding cities. 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.

Safety and Regulation

Underground construction has a number of unique risks and challenges but shares a lot with traditional construction and mining. 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 OSHA first adopted unique regulations for underground construction in 1971. OSHA regulates underground construction by companies and federal agencies but does not regulate underground construction activities associated with mining.

Tunnel construction

Tunnels are the most common man-made subterranea. They have been constructed by various means since prehistory.

Military construction

Modern underground military facilities emerged during the second world war and pre-war period. During the later years of WWII Nazi Germany moved much of its military industry underground. The Nazis used prisoners of war and slave labor to build their underground structures and large numbers perished during construction.
The cold war brought about brought about two new underground structures, the nuclear powers built missile silos and all world powers built leadership protection bunkers in response. Examples of the latter include the Cheyenne Mountain Complex, Metro-2, and the Underground City.