Beam Shear Capacity
The footing beam shear capacity is only checked for beam shear perpendicular to the continuous footing major direction. The shear is checked at all locations along the footing up to a distance of d from either side of the supported column or wall. The shear is also checked at the column or wall face so the concrete shear capacity at d can be properly calculated.
The shear on the footing is recovered from the Finite Element analysis on the beam elements.
The Section shear capacity is calculated using the method outlined in "Beam Shear Capacity" for Spread Footings.
Unlike spread footings, continuous footings can have shear reinforcement. The required shear reinforcement is calculated as indicated below:
The Nominal shear capacity is defined as:
| Vn = Vc+ Vs |
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 per BS8110.
| Section 6.3.1 in Reference #4 |
| ≤ 5 N/mm2 | BS8110: Part 1, Section 3.4.5.2 |
| smax > (hagg + 20)/db + db | BS8110: Part 1, Section 3.12.11.1 |
| smax ≤ 3/4d | BS8110: Part 1, Section 3.4.5.5 |
Where the required shear capacity is more then half the concrete shear capacity Vc shear reinforcement is provided per BS8110: Part 1, Table 3.7.