Proposed Material Requirements for Category 3 Members in Seismic-Resisting Systems

The New Zealand Steel Structures Standard states that high strength structural bolts shall be supplied to AS/NZS 1252.

30 November 2020

The Steel Structures Standard material provisions for seismic applications are intended to ensure that the grade of steel chosen can meet the expected inelastic demand in both seismic and non-seismic applications (SNZ, 1997a). This includes suppressing brittle failure. The current NZS 3404 1997/2001/2007 material requirements are identical for category 1, 2, and 3 members, even though the inelastic seismic demand from category 3 members is much lower than that from category 1 and 2 members. This lack of differentiation of material requirements has created problems sourcing compliant steels for seismic-resisting systems.


Alistair Fussell, Kevin Cowie, Dr Michail Karpenko, Dr Charles Clifton