Coal minesRoofsGeologic processesHazardsUnderground supportingRock boltsKettlebottoms are columnar masses of rock--the preserved casts of ancient tree stumps--embedded in coal mine roof strata (of which they are a part). Because unsupported kettlebottoms can detach from mine roof without warning, ...
Kettlebottoms: their relation to mine roof and support: Chase, F E; Sames, G P US Bureau of Mines reportRI 8785, 1983, 12Pdoi:10.1016/0148-9062(84)90948-3NoneELSEVIERInternational Journal of Rock Mechanics & Mining Sciences & Geomechanics Abstracts...