Isolated Column Footing Design in Excel

Isolated Column Footing Design in Excel - USD Method

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

Download file: Isolated Footing Design Excel Sheet Based on ACI 318. You also know how to design Wall Footing in Excel Sheet USD method. If any problem for calculated this design, comment below, Thank you.