No Special Tools Required

The project is a key part of Victoria’s Big Build, designed to reduce traffic congestion and enhance transport connections. This significant infrastructure development faces various complex structural engineering considerations. A crucial component is the suspended ceiling system within the tunnel, where undercut anchors are essential, providing reliable support for the jet fans.

Undercut anchors are essential for their strength and longevity in applications with sustained loads. Designed for high loading capacity and stability, these anchors mechanically interlock with concrete, securing a reliable connection that reduces the risk of load-related failures.

Allfasteners’ UAP-S Pre-set Undercut Anchors excel in their installation method. Similar to wedge anchors that expand to secure into concrete, UAP-S anchors are tightened to undercut the concrete as they are installed. This self-undercutting action streamlines the installation, reducing the need for extra special tools and steps. It ensures a secure mechanical interlock, providing reliability on par with cast-in anchors, which have proven effective in major tunnel projects.

Case Study: Tunnel Ceiling Suspension System

Allfasteners actively tackled the challenge of supplying an anchor suitable for the ceiling suspension system in a Melbourne tunnel project.

After thorough testing and verification, the engineering team chose the UAP-S Pre-set Undercut Anchor for its robust performance under sustained loads.

The UAP-S anchors’ ease of installation sets them apart from the competition. Traditional anchor installations involve labour-intensive manual undercutting and setting tools.

In contrast, the UAP-S anchors eliminate the need for special tooling, which not only speeds up the installation process but also cuts down on labour costs.

For this particular project, large quantities of anchors were installed, each equipped with filling washers, locknuts and custom made oversized washers to effectively transfer the load from the anchors to the support plate.

Using filling washers proved beneficial, they enabled the void filling of slotted holes and the sharing of the shear load amongst all anchors, thereby enhancing the structural integrity of the ceiling suspension system.

Combined with lock nuts, these components also contributed to improved vibration performance, a critical factor in ensuring the long-term durability and safety of the tunnel’s infrastructure.

The Necessity of Undercut Anchors

Historical lessons, such as the tragic Boston Big Dig Ceiling Collapse in 2006, where a heavy concrete ceiling panel fell due to an older type chemical anchor failure, killing one and injuring another, have profoundly shaped current construction practices. The investigation into this disaster highlighted the vulnerabilities of chemical anchors available at that time, which can creep under sustained loads, leading to catastrophic failures.

These insights have shifted industry focus towards more reliable solutions like undercut anchors, especially for critical applications like suspended ceilings in tunnels. The industry’s shift towards specifying undercut anchors, which are designed to meet a 100-year lifespan, reflects a broader commitment to long-term safety and effectiveness.

Allfasteners’ Role: A Partnership Built on Trust and Expertise

During the project, Allfasteners’ engineering team worked closely with the client to design the UAP-S Pre-set Undercut Anchors for the jet fan suspension system. Through the collaboration, we demonstrated our expertise and reliability in specialised fastening solutions, impressing the client with our meticulous approach and authoritative knowledge in the field, which solidified our role as a trusted partner.

Our initial success with the UAP-S anchors has grown and deepened our partnership with the client, further cementing our status as the go-to For All Things Fixings.