The analysis follows the specifications in the standard AS 3600: 2018 Clause 9.3, but the major part of the design is based on the research presented by F K Lim and B V Rangan. Please note that AS 3600: 2018 does not have a specific clause on shear stud design. Therefore the software is based on a research paper. Leviat recommends the shear stud design is verified against an alternate standard, such as BS EN 1992 Eurocode 2, which is also available in the software.
The shear capacity of the slab is checked against the design shear forces at the critical shear perimeter (refer to AS 3600: 2018 for further details on determining the critical shear perimeter) and if required Shearfix studs are designed to increase the shear capacity of the slab.
The first stud is positioned between 0.35d – 0.5d from the column face. The stud spacing is a minimum of 75% of the slab thickness, 70% of the stud height and 500mm.
The software checks the punching shear resistance with two studs per rail first and continues adding more studs until the shear resistance of the slab exceeds the applied punching shear load.
The last control perimeter for the verification is located at a distance d/2 beyond the outermost shear stud of each rail.
The spacing between individual rails is limited to a minimum of the slab thickness and 600mm.
Shearfix Calculation Method (PDF, 58.9 KB)
Effect of Slab Penetrations
Where there are openings in the slab within 2.5b0 (b0 = width of an opening) from the critical shear perimeter (cl. 220.127.116.11), a section of the slab will be ineffective and the critical shear perimeter will need to be reduced. The design program allows reductions to be applied to the critical shear perimeter as appropriate.
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Leviat has released an enhanced version of its popular Ancon Shearfix design software that enables engineers to maintain a flat concrete slab at column heads by reinforcing the area against punching shear with a prefabricated, stud-rail system.