Update to designing post-installed anchors for seismic conditions

With the latest update to AS5216:2021 and the addition of Appendix F: Design of fastenings under seismic actions, Australian design and building experts are now able to have clarity on qualification, selection and design of post-installed anchors intended to be used to resist seismic loads.

While AS1170.4 has been around for a while and has even been updated in 2018 to further improve design of buildings and components for seismicity, the post-installed anchor standard AS5216:2018 did not include any mention of seismic design. This was until 2021.

With the revision and addition of Appendix F in AS5216:2021 we now have:

• Qualification in the form of European Technical Assessment (ETA approvals) linked to formal EADs (330232 for mechanical and 330499 for chemical anchors) with detailed description of the stringent testing methodology outlined in EOTA TR049
• Selection of the product according to crack width assessment or building importance level following NCC definitions
• Design calculations for tension, shear and/or combined loading as stated in AEFAC TN10 as referenced in AS5216:2021

As a quick summary, post-installed anchors to be used for seismic design conditions should have extended ETA approvals covering either C1 or C2 categories. While there are more involved in the qualification and testing of these categories, one of the main variable is the crack width tested. We all know standard cracked concrete condition is a 0.3mm crack. C1 category increases to a 0.5mm and C2 to 0.8mm crack width.

Another good summary to view standards for different components and load conditions:




Hilti has been actively bringing the above message to the industry and have been supporting design engineers and building experts via seminar/webinars or direct project or design consultation. Our team of engineers are readily available for such support and should you require or are interested in our services please reach out to us via LINK

We have also developed a landing page for all things seismic on our website and have a free to download leaflet/brochure to serve as a quick guide on dealing with seismicity in post-installed anchors as well as breakdown of available or suggested products.

Additional Resources:
Seismic resource page - Hilti's Seismic leaflet for download and additional information
PROFIS Engineering page - Hilti's design software incorporating AS5216:2021 and more
European Organisation for Technical Assessment (EOTA) resources - EADs and TR049
AEFAC Resources - TN10 Prequalification and design requirements for fastenings under seismic actions