One-Way Shear in Continuous Footings

One-way shear design is conducted for sections perpendicular to the continuous footing major direction. The shear is checked at all span locations along the footing up to a distance of d/2 from either side of supported columns or walls. The capacity calculation is performed according to the method outlined in Section 4.10.1.

Unlike spread footings, continuous footings can have shear reinforcement in RAM Foundation. The required shear reinforcement is calculated as indicated in the following.

With reference to Equation ACI 318-14 14.5.1.1(c) the nominal shear capacity can be defined as:

V_{u} = V_{c} + V_{s}

Equation ACI 318-14 22.5.1.1

Shear reinforcement is taken to be provided by reinforcement stirrups with a user defined number of vertical legs. There are no minimum reinforcement limits enforced as footings are exempt from the limits in ACI 318-14 7.6.3.1.

Shear reinforcement capacity is calculated as:

V_{s} = \frac{A_{v} f_{y} d}{s}

Equation ACI 318-14 22.5.10.5.3

Which is limited by:

V_{s,max} = 8 \sqrt{{f^{'}}_{c}} b d

ACI Section 11.5.6.8

Shear reinforcement spacing limits:

s ≤ d/2 and s ≤ 24 in.

ACI 318-14 Section 10.7.6.5.2

If $V_{s} \geq 4 \sqrt{{f^{'}}_{c}} b d$ , then must be reduced by one-half per ACI 318-14 Section 10.7.6.5.2.