Accessories PNEG-318 Owner's manual
148 PNEG-318 Concrete Foundation Recommendations for GSI Grain Bins
19. Commercial Tank Foundation Tunnels
4 x 4 Tunnels
64' Maximum Sidewall Height (24 Rings 2.66" Corrugation) 3000 PSI
Concrete at 28 Days ASTM A615 Grade 60 Deformed Reinforcement Bar
1. Lap all bars 35 bar diameters and stagger all laps in plan 3'-0".
2. Material estimates are approximations only. Estimates do not include allowances for reinforcement
bar overlaps, concrete shrinkage or material waste.
3. Reference drawing 4 x 4 - 64' for construction details and rebar/beam drawing for rebar/beam details.
4. Concrete should have a minimum compressive strength of 3000 PSI at 28 days.
5. Based on a soil bearing capacity of 3500 PSF.
When a tunnel is added to the inverted âTâ foundation, increased stemwall height is required in all cases.
The footer must be kept below the frost line to minimize movement.
Diameter #4 Rebar #5 Rebar #6 Rebar Concrete
Ft. Ft. Lbs. Ft. Lbs. Ft. Lbs. Yd^3
27 1300 868 400 417 500 751 23
30 1400 935 400 417 600 901 25
33 1500 1002 400 417 600 901 27
36 1700 1136 500 522 700 1051 30
39 1800 1202 500 522 700 1051 32
42 1900 1269 600 626 700 1051 34
45 1900 1269 600 626 700 1051 36
48 2200 1470 600 626 800 1202 39
54 2200 1470 700 730 900 1352 42
60 2700 1804 700 730 1000 1502 48
72 3200 2138 900 939 1200 1802 58
75 3300 2204 900 939 1300 1953 60
78 3400 2271 900 939 1300 1953 62
90 4000 2672 1100 1147 1500 2253 72
105 4600 3073 1200 1250 1800 2704 83
Diameter Beam
72' and Under W8 x 58
75' through 90' W8 x 67
105' W10 x 77