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Basic Technical IVT Commonly tested

Slope Angle of Repose

noun

Pronunciation: /sloʊp ˈæŋɡəl əv riˈpoʊz/

The steepest angle at which unconsolidated material such as spoil, tailings, or fill remains stable without sliding under gravity. This angle varies based on material grain size, moisture content, and friction properties, typically ranging from 30 to 45 degrees.

Plain English

The maximum slope steepness of loose material like mine waste that can stand safely without sliding down.

Etymology & History

Origin languageEnglish
Rootslope (from Dutch slopen) + angle (from Latin angulus) + repose (from Latin reponere)
First recorded use1850s
Usage frequencyCommon

Usage

"Reclamation engineers designed spoil piles with slopes matching the angle of repose to prevent erosion and mass failures."

Style guide notes: Always provide specific degree measure or material type when referencing angle of repose.

Also known as

friction angle slope stability angle natural slope

Contrasted with

unstable slope critical slope height

Related Terms

Frequently Asked Questions

How is angle of repose determined for mine reclamation?

Laboratory testing of spoil material samples measures internal friction angles and field observations validate stable slope configurations.

What happens if slopes exceed the angle of repose?

Material slides downslope creating erosion, unstable landforms, increased sediment transport, and potential safety hazards to personnel or structures.

Why Test Candidates on This?

Fundamental parameter for safe design of surface mine waste piles and reclaimed landforms.

Required skill level: Junior

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