Grain Storage: Silos, Bins & Pressure Distribution
Subtopic: Shallow bin vs deep silo criteria
Question Statement:
Which of the following criteria distinguish a deep silo from a shallow bin in agricultural grain storage engineering?
Options:
(A) In a deep bin, the rupture plane of the stored grain intersects the opposite vertical wall before reaching the free grain surface
(B) In a shallow bin, Airy's or Coulomb's formula applies where the rupture plane emerges at the free grain surface
(C) Wall friction supports a major fraction of the grain weight in deep silos, preventing hydrostatic pressure buildup
(D) In a deep silo, the bottom floor carries $100\%$ of the total grain mass regardless of silo height
Answer Key:
A, B, C
Step-by-Step Solution & Explanation
1. Deep bin definition: plane of rupture intersects the opposite side wall (A is true).
2. Shallow bin: plane of rupture breaks out at top free surface (B is true).
3. Janssen wall friction takes up majority of grain mass, causing pressure saturation (C is true).
4. In deep silos, wall friction supports over $70-90\%$ of total grain mass at depth; floor carries only a minor fraction (D is false).