Q1 Silo Wall Loads

The axi-symmetric (conical) silo of Figure 1 is designed to handle GOLD ORE at 7.2% moisture content. You are asked to determine:

(a) The initial vertical and normal wall pressures as a function of bin height during filling of the silo using the methodology presented in Australian Standard AS3774-1996.

For the cylindrical section of the silo is k = 0.37.

For the hopper section, the pressure ratio is given by

(b) The vertical and normal wall pressures as a function of bin height for the flow case in accordance with AS3774, but using the modified khf value for the hopper pressures as given by:

For the normal pressures on the cylinder walls during flow, the over-pressure factor (cnf) based on the Janssen pressure should be used (Refer to notes)

The following information is given:

Wall friction angles -

φw for Mild Steel = 34°

φw for Arcoplate = 23°

Effective angle of internal friction δ = 52°

Bulk density, ρ = 1850 kg/m3

The angle of repose of the GOLD ORE is 38°. The silo is initially centre filled.

NOTE: The wall load results determined are to be plotted against the height of gold ore in the silo.

All parameters used for calculating the wall loads are to be provided.