DESIGN OF BINS. 



Ore pockets on the Great Lakes arc made with hopper bottoms at an angle of 48 40' to 

 50 45', but the majority are at an angle of 49 45'. Bituminous coal will slide down a steel 

 chute at an angle of 40 and a wooden chute at an angle of 45. Anthracite coal will slide down a 

 Mr -1 chute at an angle of 30 and down a wooden chute at an angle of 35. 



.t_ 



FIG. i v {. ELEVATION CIRCULAR STEEL ORE BIN FOR OLD DOMINION COPPER MINING Co. 



DESIGN OF BINS. Bins are usually subjected to sudden loads and vibrations and should 

 be designed for two-thirds the allowable unit stresses for dead loads given in 33 to 41, inclusive, 

 in "Specifications for Steel Frame Buildings," Chapter I. 



Bins are made of timber, of structural steel, or of concrete, or the different materials may 

 be used in combination. 



FLAT PLATES. The analysis of the stresses in flat plates supported or fixed at their edges 

 is extremely difficult. The following formulas by Grashof may be used: The coefficient of lateral 

 contraction is taken as \. For a full discussion of these formulas based on Grashof "s "Theorie 

 Der Elasticitat und Festigkeit" see Lanza's Applied Mechanics. 



I. Circular plate of radius r and thickness t, supported around its perimeter and loaded with w 



