Grain Storage: Silos, Bins & Pressure Distribution
Subtopic: Janssen silo pressure asymptote
Question Statement:
According to Janssen's theory for grain pressure in deep storage silos, the vertical pressure at great depths asymptotically approaches a constant maximum because:
Options:
(A) Frictional shear forces along the silo wall support the weight of the additional grain column
(B) Grain density drops to zero at the bottom
(C) Atmospheric pressure pushes upward against the hopper
(D) Grain liquefies under stress
Answer Key:
A
Step-by-Step Solution & Explanation
Wall friction carries the weight of upper grain layers: $L_{\text{max}} = \frac{w R}{\mu' k}$, causing vertical pressure to plateau asymptotically rather than increasing linearly like liquids.