Athol Love [13/8/2020]

Feedback on Reports AUS-4 and AUS-22 Light gauge steel truss fabrication issues

Re light cold formed trusses, Load path eccentricities are common. I suggest that some full scale loading to failure might point the way to acceptable detailing.

G Charles Clifton [3/3/2020]

Feedback on Report AUS-4 Light steel truss issues

I teach cold formed steel design at the University of Auckland and have been a technical advisor to NASH New Zealand since its formation in 1989. Cold formed steel framing is an incredibly versatile material to work with and, properly designed and detailed, it delivers dependable structural solutions with a strength to weight ratio far superior to other structural materials. However, it is also a challenging material to design, especially at a system level and one in which the load transfer through connections must be very well understood and applied. This is especially the case where elements in a member cross section are removed to allow one member to connect into another. It is extremely important that the loads to be transferred through the connections are accurately quantified and the load paths well understood. Only then can the designer be certain that the connection components carrying the loads can transfer these as intended. This is vital in all steel construction and especially in multi-member connections in light steel framed systems. It is not something that can or should be covered in AS/NZS 4600 but it relies on the experience of the design engineer to both perform an adequate design and then to document this to the fabricator so it gets built as the designer intended. The fabricator must then build the system in accordance with the drawings. When this is done, the cold formed steel system will deliver excellent structural performance. When it is not done correctly, there are many ways in which the performance can be compromised.

Russell Keays [27/2/2020]

Feedback on Report AUS-13 Dislodged finger plate on highway bridge

The report AUS-13 about a dislodged finger plate reminded me that I have noted broken finger joints on an expansion joint in a bridge structure and that this could lead to a blown tire and the potential for a serious crash of the vehcles involved.

Professor Gregory Hancock AM [3/4/2019]

Feedback on Report 390 Fabrication issues with imported steelwork truss in Australia

As Chair of Standards Australia Committee BD/1 which is responsible for AS 4100 Steel Structures, and AS/NZS 5131 Structural Steelwork – Fabrication and Erection, we are in the process of a major revision to these standards to deal with some of the issues cited.

Basically we are removing fabrication and erection provisions from AS 4100 and including most of them as appropriate in AS/NZS 5131. We are then making direct reference to AS/NZS 5131 from AS 4100. The main intent of this is to make AS/NZS 5131 a secondary reference to AS 4100 within the National Construction Code. This means that AS 4100 can now include reference to the construction specification as the document containing the particular design data and details to be provided as one deliverable from the design process.

The revised standards are expected to go out for public review in May 2019. It is hoped that the revised standards go some way to address some of the issues raised by CROSS-AUS.

Geoff Fletcher [26/9/2018]

My sincere congratulations to all who contributed to achieve the launch of CROSS-AUS, not least to IStructE for its support. Better engineering will be the winner, and its service to society.