10 BULLETIN 789, U. S. DEPARTMENT OF AGRICULTURE. 
DETERMINATION OF VERTICAL AND LATERAL PRESSURES IN GRAIN 
BINS WITH HORIZONTAL REINFORCING FOR CYLINDRICAL CON- 
CRETE TANKS BY MEANS OF PLATE IL. 
By means of the four curves on the chart in Plate II, which have 
been plotted from values given by Tables 1 and 2, the vertical and 
lateral unit pressures may be determined for any bin, and in the 
case of cylindrical concrete tanks the size and spacing of the hori- 
zontal reinforcing may be obtained without the need of any calcu- 
lations. 
The manner in which this chart may be used can best be explained 
by means of several examples, which will be first solved mathe- 
matically, using the values given by Tables 1 and 2, and then directly 
from the chart. 
EXAMPLES SHOWING USE OF PLATE II. 
EXAMPLE 1. 
Required: The vertical and lateral unit pressures at the bottom in 
a round or square bin 15 feet in diameter and 75 feet in height. 
Hm, 
D Fah 
H 
From Table 1: For — = 
D 
Mie 49.66 and V=15 X 49.66 =745 pounds per square foot. 
+ =20.79 and L=15 x 29.79 =447 pounds per square foot. 
From Plate IT: Follow the vertical line at the right-hand side for 
diameter 15 feet upward to its intersection with the oblique line 
representing 75 feet for the height of the grain. This will be found 
to be on the heavy horizontal line fourth from the bottom of the 
page. Follow this horizontal line to the left to its intersection with 
curve 1. Project from this intersection vertically to the line for 
diameter 15 feet of the set of radial lines for pressures. This last 
intersection will be found to be horizontally opposite a point on the 
scale for pressures a little above the line for 750 or about 745 pounds 
per square foot, which equals the unit vertical pressure. Returning 
to the fourth heavy line from the bottom, continue to the left to its 
intersection with curve 4, again project vertically to radial line 15 
for pressures, then horizontally to the right to a little above the line 
for 450 or about 445 pounds per square foot, which equals the unit 
lateral pressure. 
