Punching shear design notes appear in Chapter 66, "Punching Shear Design Notes".

Non-Standard Sections: ACI 318 and CSA A23.3

Some times the punching shear status is "Non-Standard Section". This is a warning, not an error. "Non-Standard Section" means that at least one of the critical sections that RAM Concept is investigating for that column does not perfectly fit one of the three cases: interior, edge and corner.

When you get a "Non-Standard Section", you need to inspect the critical sections that RAM Concept has defined, and use your engineering judgment to determine if you feel they fit the ACI/CSA punching model (you should always visually inspect the critical sections, even if RAM Concept does not flag them as non-standard). RAM Concept still calculates a stress ratio for non-standard sections.

Non-Standard Sections: AS3600, BS8110, EC2 and IS 456

Some times the punching shear status is "Non-Standard Section". This is a warning, not an error. "Non-Standard Section" means that at least one of the critical sections that RAM Concept is investigating for that column does not perfectly fit one of the three cases: interior, edge and corner.

When you get a "Non-Standard Section", you need to inspect the critical sections that RAM Concept has defined, and use your engineering judgment to determine if you feel they fit the code punching model (you should always visually inspect the critical sections, even if RAM Concept does not flag them as non-standard). RAM Concept still calculates a stress ratio for non-standard sections.

If a punching section can be classified by any of the "standard" rules, it is considered to be a "standard" section. The rules for "standard" sections are:

1. Interior Rectangular:
   • must be uniform thickness
   • must have 4 sides
   • section centroid must coincide with column centroid
   • opposite sides must be parallel and have same length
   • adjacent sides must be perpendicular
   • must be continuous (no gaps)
2. Edge Rectangular:
   • must be uniform thickness
   • must have 3 sides
   • opposite sides must be parallel and have same length
   • adjacent sides must be perpendicular
   • can only have two discontinuous ends (assumed at slab edge)
3. Corner Rectangular:
   • must be uniform thickness
   • must have 2 sides
   • sides must be perpendicular
   • can only have two discontinuous ends (assumed at slab edge)
4. Interior Round (circular shape idealized into straight line segments):
   • must be uniform thickness
   • section centroid must coincide with column centroid
   • all segment ends must be on same radius from the center of the column
   • must be continuous (no gaps)
5. Corner or Edge Round (circular shape idealized into straight line segments):
   • must be uniform thickness
   • column must be round
   • can only have two discontinuous ends (assumed at slab edge)
   • can only have two segment end points that are a different radius from the center of the column than all other segment end points (assumed at slab edge)
   • discontinuous segment end points must be the “off radius” points (at slab edge)