ACI 318-19 Section 16.5 | Corbels and Brackets Design
Corbels are short cantilevers projecting from column faces to support precast beams or crane girders with shear span-to-depth ratio (av/d) ≤ 1.0. They behave like deep struts rather than standard flexural beams.
Governing Formula
Check Automatically
AXIS verifies ACI 318-19 limits directly inside your models with full step-by-step math.
Notation & Variables
Worked Example
Verify geometric limits
Check that shear span ratio av / d ≤ 1.0, and that factored horizontal tensile force Nuc ≤ Vu.
Calculate shear friction Avf
Compute shear friction steel using friction coefficient μ = 1.4 for monolithic concrete.
Determine primary and closed tie steel
Select Asc as the governing envelope and provide closed stirrups Ah distributed within 2/3 d below Asc.
When does this govern?
Heavily utilized in precast concrete warehouse framing, parking garages, and industrial crane runway column bents.
Common Mistake
Forgetting the mandatory minimum horizontal tensile force Nuc ≥ 0.20 Vu to account for restrained thermal expansion and creep of supported precast girders.