Underground space
development is one possible way to help solve urban problems such as
congestion, lack of open space, and an aging infrastructure. What is sometimes
referred to as underground architecture may in reality be earth-sheltered,
earth-beamed, or earth-covered, rather than below the natural ground surface.
Terms used to describe structures constructed in underground spaces include semi
subterranean, subterranean, geotectural, lithotectural (i.e., mined
rock-enclosed space), petratectural (i.e., covered with rock), psammotectural
(i.e., covered with sand), argillatectural (i.e., covered with clay), and
terratectural (i.e., earth-covered architecture, in which a building is
constructed within an excavation, waterproofed and then back filled and
earth-covered).
Acknowledgement :
http://fc04.deviantart.net/fs70/i/2012/277/5/8/underground_architecture_by_sshony-d5gqsdm.jpg