Engr. Balaram| Isolated Column Footing Design in Excel |
Hi, I'm Engr. Balaram. I share an Isolated column footing design calculation excel sheet in free. This design calculated in the Ultimate Strength Design method.
How to design isolated column footing in an excel sheet:
Step - 1: Insert data like fig-01
Step - 2: Footing Size
Since the space between the bottom of the footing and the surface will be occupied partly by concrete and partly by soil (fill), the average unit weight of 125 lb/ft3 will be assumed.
Step - 3: Thickness
Assuming, d = 20.50 in ( assuming sum of (L+B) in the unit of inch)
Step - 4: Punching Shear Check
Factored Load from Colm, Pu = 494.00 kip (Taken from Staadpro)
Upward pressure caused by the factored load of the column, qu = Pu / (LxB) = 5.78 ksf.
The footing depth in square footings is usually determined from the two-way or punching shear on the critical perimeter "abcd". Trial calculation suggests d = 20.50 in.
Step - 5: Beam Shear Check in the Long direction (L)
The selected value d= 20.50 in will now be checked for one-way or beam shear on section "EF".
The factored shear force acting on that section is:-
Step - 6: Beam Shear Check in the Short direction (B)
The selected value d= 20.50 in will now be checked for one-way or beam shear on section "IJ".
The factored shear force acting on that section is:-
Step - 7: Bending Moment in the Long direction (L) or on section "GH"
= 5858666.67 lb-in
Step - 8: Bending Moment in the Short direction (B) or on section "KL"
Step - 9: Check "d" considering Max moment
Step - 10: Steel requirements in the Long Direction (L)
Step - 11: Steel requirements in the Short Direction (B)
shall be uniformly distributed across a bandwidth, B centered with respect to the column and having a width equal to the length of the short side of the footing, The reminder of the reinforcement shall be uniformly distributed in the outer portion of the footing.
Step-12: Development Length for footing in the long direction (L)
Step - 13: Development Length for footing in the Short direction (B)
Step - 14: Development Length for Column
Step - 15: Final Design
| Isolated Column Footing Design in Excel - USD Method |
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