The VertiBrace (when designed and installed in full compliance with the Design Guide) will meet the B1 structure provisions in the New Zealand Building Code.
VertiBrace Design Capacity:
The design capacity of the VertiBrace for use with ULS loads is:
*The capacity calculated to date only applies when the tested conditions are satisfied:
Headtrack type: 92mm x 0.75BMT steel
Brace arms: 64mm x 0.5BMT lipped stud
Linings: 2 x 13mm GIB Standard
The design capacity has been determined by applying a sampling factor to the minimum tested capacity, as specified in AS/NZS 1170.0:2002 - Appendix B.
Type 1 Test
The Type 1 Test was carried out using 92x0.55BMT steel stud brace arms to determine if wider stud brace arms will behave differently under load.
The Type 2 Test was carried out with a higher wall and brace height, to verify that the stud capacity calculations to AS/NZS 4600 are accurate. A summary of the results from the two tests is below:
The 92mm stud failed by being crushed at the brace connection point. This allowed the brace system to rotate, which led to the stem slipping out of the barrel. This failure mode is slightly different to that of 64mm stud (64mm stud does not usually crush at connections due to the closeness of the flanges), however the tested capacity of 3.58 kN is close to the average tested capacity of 64mm stud.
Although the failure mode has changed when compared to 64mm stud brace arms, the use of 92mm stud is acceptable for the following reasons:
- The crushing of the steel stud occurred at the maximum test load of 3.58kN.
- Based on this test there is a factor of safety of 1.5 on the VertiBrace design capacity
- The compressive capacity of the steel stud will be calculated using AS/NZS 4600, which adds an additional reduction factor of 0.85 on the stud capacity
Type 2 Test
The Type 2 Test was carried out to validate the calculated compressive capacity of steel stud. 64x0.5BMT steel stud was used for the brace arms, and the studs were 1700mm long. The expected compressive capacity of the stud has been calculated to be a minimum of 3.28 kN (to NZS4600).
Left: Unloaded. Right: Approximate SLS loading (20mm horizontal deflection)
At the maximum test load of 3.69kN, there was no visible buckling or deformation in the steel stud brace arms. The calculated capacity of the steel stud to NZS 4600 is 2.32 kN. Therefore based on this test, the stud capacity calculations to AS/NZS 4600 are conservative.
Please Note: There are currently no specific statutory requirements that apply to non-structural internal partitions in commercial buildings and a building consent is not required to install non-structural partitions. Nevertheless, all building work must comply with the Building Act 2004 and the New Zealand Building Code. Non-structural partitions should be able to perform at least as well as the building structure in a low or moderate earthquake event. That is, if the building structure is not damaged, there should be no or minimal damage to interior partitions.