Spread Footing Design Example

This section provides a spread footing design example covering the topics discussed in Section 4.10. The procedure shown here is intended to illustrate the methods used internally within RAM Foundation to arrive at a final spread footing design.

Geometry for spread footing design example

Spread Footing Parameters:

Design Code: ACI 318-02
Design for Actual Footing Forces
q_a = 4,000 psf
f '_c = 3,000 psi
r_c = 150 pcf
f_y = 60 ksi
Clear Cover = 3 " (all sides)

Flexural Bar Sizes Considered: #4 through #6

Applied Loads:

18 "x18 " Supported Column
P_D = 250 k
P_L = 125 k
M_E = 1200 k-ft (major footing direction)

Note: The user has the option to select Include Moment Due to Shear in Column in the Design tab within the Design Criteria menu. If this is done, the value ME shown above would include the column shear multiplied by the footing thickness.

Load Combinations:

Soil Combo: 1.0D + 1.0L + E/1.4
Concrete Combo: 1.2D + 0.5L + 1.0E

Optimized Footing Dimensions:

Footing Width = 15 '-0 "
Footing Depth = 2 '-6 "