- published: 14 Jul 2009
- views: 1645507
A cave-in is a collapse of a geologic formation, mine or structure which may occur during mining or tunneling. Geologic structures prone to spontaneous cave-ins include alvar, tsingy and other limestone formations, but can also include lava tubes and a variety of other subsurface rock formations. Glacier caves 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 a many types of collapses, ranging from the fall of a single flake of shale to collapses that form sink holes that reach to the surface. However, roof falls in mining are not all accidental. In longwall mining 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, but rather to control it.
Cave In
Anchor
Whatever makes you tired, the resting always fails
Because anywhere you lay yourself's a bed of nails
Whenever you exhale, I breathe it in the air
You offer me a seat in your electric chair
Are you safe to leave behind every anchor in your mind?
You know better than I do, so clue me in
And every day you ask yourself, "Why was I born?"
Because every migraine feels like wearing a crown of thorns
And all the time I find you crawling on all fours
Because any movement sends you falling through trap doors
Are you safe to leave behind every anchor in your mind?
You know better than I do, so clue me in
Your tongue in cheek
Too late it's already days and weeks before we can make ends meet
Am I right? And you're wrong?
Too late it already takes too long, too much to be flushed with you
Oh, too much to be flushed with you
Whatever makes you tired, the resting always fails
Because anywhere you lay yourself's a bed of nails
Are you safe to leave behind every anchor in your mind?