Post-installed anchors, direct fastening and passive firestop designs for tunnel construction projects can quickly become complicated. Not only are there a wide range of applications to deal with but also such projects usually require stringent technical requirements to be met, ensuring they comply with industry requirements and regulations.

Hilti aims to simplify this process with a wide range of products, services, and software suitable for many different types of tunnels and applications.

Post-installed anchoring applications in tunnels

With an extensive range of anchoring applications, tunnel projects might require fixings from light duty temporary services to heavy structural applications that require a 100-year design-life. Different solutions are required during all construction phases, from as early as the site installation.

The image below shows a range of fixing applications for such projects.



Hilti has extensive local experience with these applications.

You can find further content on these topics in the links below:

• Editorial on seismic design: click here 
• Upcoming webinar on fire design: click here
• Upcoming webinar on durability: click here 

Power Actuated Fasteners

Additional types of concrete fixing applications that are mainly used for light duty or temporary applications are powder actuated fasteners (PAF), or direct fasteners. Although these fixings are not currently covered by the Australian anchoring code, AS 5216:2022, there have been recently publications by the Australian Engineered Fasteners and Anchors Council on technical note 11, volumes 1 and 2 for both safety critical and non-safety critical applications in-line with European regulation.

Some of the relevant applications for PAF in tunnels include, but are not limited to, fixing waterproofing above the tunnelling surface before the concrete lining is poured, early shotcrete strength testing, wire mesh before shotcrete is sprayed and temporary services and fixings as shown in the image below.



PAF also comes in various coatings and material grades and durability considerations should be adopted as per the project requirement.

Passive Fire Protection

Due to the potential of high occupation during the operation period and limited evacuation routes during fire events, the planning, design and execution of the passive fire protection system is of the highest relevance.
 
Hilti has a complete range of passive fire stopping solutions that can seal services penetrations not only at underground stations, but also at service rooms, cross passages and in auxiliary buildings.

Hilti has recently partnered with UL Solutions to obtain local third-party product certification under the UL-AU scheme, which is accredited by JAS-ANZ. This certification means that continuous surveillance is performed by UL-AU to guarantee the quality of our products which means less risk for those who specify, install and inspect firestop systems.

You can learn more about the third-party certification of our firestop systems by reading this article: click here.

Application design assistance for tunnel projects

Hilti experts are available to consult and advise you during the design and construction phases, whether at your office or on the jobsite. We have invaluable experience that informs our design recommendations and can support with your design challenges. In addition, our specialized project teams can help you to reduce the risk of rework as well as increasing productivity during construction. Get in touch with us today for technical support: click here.


The information provided in this article is for general information purposes only. While we strive to ensure the accuracy and reliability of the information presented, it is not intended as legal, technical or professional advice.
 
Hilti makes no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, or suitability, with respect to the article for any purpose.