A cave-in is a

collapse Collapse or its variants may refer to: Concepts * Collapse (structural) * Collapse (topology), a mathematical concept * Collapsing manifold * Collapse, the action of collapsing or telescoping objects * Collapsing user interface elements ** ...

of a geologic formation, mine or structure which may occur during mining, tunneling, or steep-walled

excavation Excavation may refer to: * Excavation (archaeology) * Excavation (medicine) * ''Excavation'' (The Haxan Cloak album), 2013 * ''Excavation'' (Ben Monder album), 2000 * ''Excavation'' (novel), a 2000 novel by James Rollins * '' Excavation: A Memo ...

such as trenching. Geologic structures prone to spontaneous cave-ins include alvar, tsingy and other limestone formations, but can also include

lava tube A lava tube, or pyroduct, is a natural conduit formed by flowing lava from a volcanic vent that moves beneath the hardened surface of a lava flow. If lava in the tube empties, it will leave a cave. Formation A lava tube is a type of lava ca ...

s and a variety of other subsurface rock formations.

Glacier cave A glacier cave is a cave formed within the ice of a glacier. Glacier caves are often called ice caves, but the latter term is properly used to describe bedrock caves that contain year-round ice. Overview Most glacier caves are started by wate ...

s and other ice formations are very prone to collapse from exposure to warm temperatures or running water. In mining, the term roof fall is used to refer to many types of collapses, ranging from the fall of a single flake of

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

to collapses that form sink holes that reach to the surface. However, roof falls in mining are not all accidental. In

longwall mining Longwall mining is a form of underground coal mining where a long wall of coal is mined in a single slice (typically thick). The longwall panel (the block of coal that is being mined) is typically long (but can be upto long) and wide. Histor ...

and retreat mining, miners systematically remove all support from under large areas of the mine roof, allowing it to settle just beyond the work area. The goal in such mining methods is not to prevent roof fall and the ensuing surface

subsidence Subsidence is a general term for downward vertical movement of the Earth's surface, which can be caused by both natural processes and human activities. Subsidence involves little or no horizontal movement, which distinguishes it from slope move ...

, but rather to control it.

Geological formations

* Alvar structures such as on the Stora Alvaret, Öland,

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

Karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

limestone such as in the Madagascar dry deciduous forests

References

Caves Mining terminology {{mining-stub