Question

A flat long wall panel is mined out at an area having subsidence factor ‘a’. The measured maximum subsidence on the surface is ‘S’ for a mining height of ‘m’. The subsidence is sub critical, if

• A. \( S = a m \)
• B. \( S = \frac{m}{a} \)
• C. \( S>a m \)
• D. \( S<a m \)

Hint:

Subcritical subsidence: \( S<a m \).

Answer 1

The Correct Option is D

Subsidence is subcritical when the observed maximum subsidence \( S \) is less than the product of mining height \( m \) and subsidence factor \( a \).