Accessories PNEG-318 Owner's manual

17. Concrete Foundation Commercial Hopper Tanks
128 PNEG-318 Concrete Foundation Recommendations for GSI Grain Bins
18' Diameter Commercial Hopper Tank Foundation up to 12 Rings
Figure 17E
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 constructed 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 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.