Grain Systems Tanks PNEG-805 - Manual (Page 17)

4. Foundations
PNEG-805 36' Diameter 40°/45° NCHT Commercial Hopper Tanks 17
36' Diameter Commercial Hopper Tank Foundation up to
18 Rings (Continued)
NOTES:
1. The foundation design is based on a minimum allowable soil bearing capacity of 3000 PSF.
Bearing capacity of the soils should be determined by geotechnical investigation and be of uniform
bearing capacity.
2. The foundation site must be free of vegetation and debris and well drained.
3. The foundation must be founded below the frost line or placed on non-expansive frost free fill.
4. All material used for backfill inside the ring wall should be clean, well graded, crushed rock or a
sand-gravel mixture. Backfill should be placed in 6" lifts, 95% compaction.
5. All reinforcement must meet the requirements of ASTM A615 grade 60 deformed bars.
6. Lap all circumferential bars 35 bar diameters and stagger all laps in plans 3'-0". Estimates for material
do not include end laps.
7. Concrete must have a minimum compressive strength of 3000 PSI at 28 days, 6%-8% air
entrainment, 4" slump.
8. Codes: UBC 97, ACI 318-95.
9. Interior top slab may be crowned 2" to provide water drainage away from foundation. Crowning the
slab will reduce the clearance under the discharge.
# of Rings Up to 10 14 18
A 1'-4" 1'-4" 1'-8"
B 6'-0" 7'-6" 9'-2"
C 14'-11" 13'-11" 12'-11"
D 20'-11" 21'-5" 22'-1"
N #5 at 12" c/c #5 at 10" c/c #5 at 9" c/c
P #5 at 10" c/c #6 at 10" c/c #7 at 8-1/2" c/c
#4 Rebar (Ft.) 2400 2400 2400
#5 Rebar (Ft.) 1500 1000 1400
#6 Rebar (Ft.) 0 1000 0
#7 Rebar (Ft.) 0 0 1400
6 x 6 - 6/6 Wire Mesh (Ft.
2
) 960 960 960
Concrete (Cu. Yds.) 75 80 110