highwall
Exposed rock surface
A highwall is the unexcavated face of rock or earth left standing after surface mining, particularly in coal strip mining.
These steep, exposed walls can reach hundreds of feet and present significant safety hazards: The mining company was fined after a highwall collapse.
Highwall mining describes a method of extracting coal horizontally from these faces.
Vertical rock wall
- escarpmentSteep slope dividing elevations
- bluffCalculated false front
- precipiceSteep rock face
- faceHead's anterior surface
ledge · outcrop · vertical · steep · exposed · ridge · crest · bench
Combustible sedimentary rock
- seamJoined fabric edge
- augerSpiral hole-maker
- extractionAct of removing
- benchShared seating surface
pit · opencast · strip-mining · overburden · recovery · reclamation · spoil · dragline
Machine that digs earth
- draglineHeavy digging machine
- shovelTool for moving earth
- loaderOne who fills containers
- bulldozerBladed vehicle pushing earth
backhoe · grader · conveyor · blasting · earthmover · crusher · scraper · bucket
Sudden structural failure
- rockfallCollapsed cliff material
- unstableProne to sudden change
- exposedOut in open
- precariousDangerously insecure
failure · slippage · fatal · accident · safety · berm · setback · inspection
Resistance to displacement
- slopeAngled terrain or steepness
- reinforcementAdding support or encouragement
- monitoringOngoing observation of something
- assessmentFormal evaluation of worth
geotechnical · analysis · failure · slippage · erosion · drainage · anchoring · bolting
cliff
Vertical rock wall
- escarpmentSteep slope dividing elevations
- bluffCalculated false front
- precipiceSteep rock face
face · ledge · outcrop · vertical · steep · exposed · ridge · crest · bench · terrace
coal
Combustible sedimentary rock
- seamJoined fabric edge
- augerSpiral hole-maker
- extractionAct of removing
bench · pit · opencast · strip-mining · overburden · recovery · reclamation · spoil · dragline · portal
excavator
Machine that digs earth
bulldozer · backhoe · grader · conveyor · blasting · earthmover · crusher · scraper · bucket · boom
collapse
Sudden structural failure
precarious · failure · slippage · fatal · accident · safety · berm · setback · inspection · warning
stability
Resistance to displacement
- slopeAngled terrain or steepness
- reinforcementAdding support or encouragement
- monitoringOngoing observation of something
assessment · geotechnical · analysis · failure · slippage · erosion · drainage · anchoring · bolting · shotcrete