Question

The sudden release of elastic strain energy stored in pillars result in violent burst of coal pillars is called

• A. Air blast
• B. Rock burst
• C. Coal bump
• D. Premature collapse

Hint:

Remember the distinction:
- Rock Burst is the general term for hard rock.
- Coal Bump is the specific term for coal.
Both describe the same physical principle: explosive release of stored strain energy.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the specific term for the violent failure of coal pillars due to the sudden release of stored strain energy.

Step 2: Detailed Explanation:
In deep mines, the immense weight of the overlying rock (overburden) creates very high stresses in the rock mass and in the coal pillars left for support.
Coal, like other rock materials, is elastic and can store a significant amount of strain energy when compressed.
-

Coal Bump (or Bump): This is the specific term used in coal mining to describe the sudden, violent failure of a coal pillar or face.
It occurs when the stored elastic strain energy is released explosively, causing the coal to be ejected with great force.
This phenomenon is a major hazard in deep coal mines.
-

Rock Burst: This is a more general term used in hard rock mining for the same phenomenon of violent rock failure due to the sudden release of stored strain energy.
While technically similar, "coal bump" is the more specific and appropriate term for the failure of coal pillars.
-

Air Blast: This is a secondary effect, a powerful gust of wind caused by the sudden displacement of air from a large rock fall or a bump.
-

Premature Collapse: This is a more general term for any structural failure that happens earlier than expected, but it doesn't specifically describe the violent, energy-driven nature of a bump.

Step 3: Final Answer:
The violent burst of coal pillars from the release of stored energy is called a coal bump.
This corresponds to option (C).