Seismic Design in Walls and Ceilings

Confused by the need for a seismic design for your walls or ceilings? What is earthquake resilience? Not sure if seismic applies to you? Bamboozled by jargon and lost by the lack of information? Relax. This article will help unravel the mystery around seismic designs and break down the complex world of earthquake resilience.

Plenum bracing on a large area seismic ceiling at new hospital project.

Seismic design and Studco

Studco are industry leaders in providing practical, simple seismic solution for walls and ceilings in buildings throughout Australia and New Zealand. For more than 30 years, Studco has been providing compliant engineered seismic solutions for important facilities such as major hospitals, government buildings, police and emergency buildings, military facilities and more. When you use Studco’s advanced seismic solution, you can build with confidence.

The case for seismic design

In certain buildings, walls, ceiling and facades constructed from light gauge steel framing system need to be designed to resist seismic loads during earthquake events. The intent of seismic design is to minimise risk to life and reduce damage to the structure. The risk to life is a straightforward argument; thinking ahead and designing for earthquakes has proven to save lives. It’s that simple. When it comes to damage to the structure, it can have a significant cost impact to rectify the damage or worse, demolish parts of the building and rebuild. Economic loss and hardship through limitation to the functionality of workspaces and habitable spaces is also common following earthquake events, even when the structure itself has not suffered substantial damage.

Heavy-duty acoustic ceiling with alternative seismic bracing in plant room at government building.

How does seismic design impact the construction?

Ceilings needs special consideration when seismic forces are present. Factors such as room size, height of the building, ceiling mass and dynamic acceleration, will influence the final design pathway taken to achieve seismic compliance. A combination of fixed/free ceiling connections at the wall junction or seismic bracing within the ceiling cavity are the most common method used is constructing suspended ceilings in seismic rated buildings.

Walls need to accommodate in-plane and out-of-plane movement and provide sufficient flexibility at junctions between walls. This can generally be achieved with simple construction techniques. Where it is not practical or economical to design walls to withstand seismic impact, we recommend installation of seismic bracing back to the structure.

The additional cost to incorporate seismic design into your building can be minimal in some instances. However, in critical infrastructure projects, the extra expense can be significant and will largely depend on the structural engineer’s experience in the specialized field of cold form steel design and their familiarity with the governing standards.

Government regulation of seismic designs

In Australia, the South Australian Government (SADEPTI) has proactively mandated seismic design in government buildings for 10 years and has released guidelines for building trades to follow. In recent years, the Queensland Building & Construction Commission (QBCC) has also been actively auditing for seismic compliance, as has the Victorian Building Authority (VBA) and the Office of the NSW Building Commissioner. In New Zealand, seismic compliance is monitored closely due to their relatively high risk of earthquakes in the region. There is a number of standards and guidelines that govern seismic design in Australia and New Zealand:

• AS 1170.4-2007: Structural Design Actions Part 4: Earthquake actions in Australia
• NZS 1170.5-2004: Structural Design Actions Part 5: Earthquake actions
• AS/NZS 2785-2020: Suspended ceilings – Design and installation
• NZS 4219-2009: Seismic performance of engineering systems in buildings
• National Construction Code (NCC) from Australian Building Codes Board
• New Zealand Building Code

Apart from risk to life, failure of ceilings during minor earthquakes can cause unnecessary damage to property, such as water damage from burst pipes and live electrical hazards.

Am I obliged to consider seismic design in my tender submissions?

Virtually all buildings new buildings are given an Importance Level rating that determines the extent of the seismic design criteria. For example, a hospital may be given the highest rating of IL 4 so that it can be used in the post-disaster recovery process whereas a small residential development may be classified as IL 1, the lowest rating. This design criteria must be taken into consideration when designing all elements within the building and design engineers are obligated to make allowance for this in their designs. Smart, practical seismic design starts with collaborative planning and intelligent coordination before the project goes out to tender. In some cases, additional costs for seismic design consideration may be significant so it’s essential that contractors know exactly what the requirements are. Late stage inclusion of seismic design can negatively impact the overall cost of a project. It is good practice to include all trades in the design coordination, including mechanical services, electrical, fire suppression systems and plumbing.

This high-risk military facility adopted Studco’s seismic design on external steel stud walls.

The Studco Seismic Solution

As a world leader in innovative building solutions, Studco has developed a comprehensive range of products and systems for use seismic designs. Seismic design solutions are available for the following Studco systems:

WALLS

• Studco Steel Stud System
• Studco Vortex Framing System
• Studco HEDA Jamb Framing System
• Studco Resilmount Acoustic Wall System

CEILINGS

• Studco Concealed Ceiling System
• Studco SlimCeil Ceiling System
• Studco Resilmount Acoustic Ceiling System

FACADES

• Studco External Steel Stud System
• Studco Top Hat Cladding System

Our seismic solutions have been developed through scientific research into past earthquakes, advances in computer simulations and analysis, component level testing, knowledge sharing with our US-based partner team and collaboration with experienced seismic engineering consultants. When Studco’s wall and ceiling systems are accompanied by project-specific engineering documentation supplied by Studco’s in-house engineering team, you can be sure that your installation meets all the necessary seismic criteria withstand an earthquake event. Don’t risk it… demand fully engineered seismic designs for your next walls or ceilings projects. 

Helpful resources for understanding seismic designs in walls & ceilings

Guidelines for suspended ceilings – BRANZ [PDF 0.95MB]

Code of Practice – Suspended Ceilings – AWCI NZ [PDF 4.5MB]

Design of non-structural building elements for earthquake forces – ABCB

Designing and building to accommodate earthquake loads – QBCC

Design of non-structural building elements for seismic purposes – SA DPTI [PDF 0.2MB]

Are you complying with the Earthquake Standard – Master Builders

If you need assistance with a seismic design or have any questions about earthquake resilience, please contact Studco’s Technical Team on 1300 255 255.