October 31, 2023
Ground support - the foundation of any project
Establishing firm foundations for an underground project is vital in terms of both safety and productivity. Normet’s ground support portfolio covers every related customer need, Martin Petranek, Director of Ground Support, says.
Managing and stabilising risks
“Working underground is inherently risky, so for us to provide top quality ground support products and services is a really important part of our overall portfolio,” says Martin Petranek. In the 6+ years he has been at Normet, Petranek has seen the ground support division develop its offering in line with industry trends and new technologies, continuing from the proven track. “Since I joined, the divisions of technical services, rock reinforcement, and construction chemicals have been combined into the ground control and construction technologies division, giving us the chance to strengthen our portfolio further and develop holistically our products.”
To ensure safe underground operations, ground control involves the use of anchors, bolts and chemicals to maintain the integrity of rock formations during complex construction, mining and tunnelling processes. “All Normet applications are closely related,” Petranek explains, “so making sure that the rock is stable is always a necessary step. Some processes such as concrete spraying and rock reinforcement can be combined to strengthen fractured or unstable strata. But the concrete spraying is only on the surface, so extra reinforcement is normally needed. You can either stabilise the strata by gluing it together with resins or combine it with rock bolting and different resins that offer various properties such as water retention or heat resistance.”
Solutions for all environments
Because ground support is almost always needed at some point, Petranek works to provide comprehensive solutions for a wide range of projects from civil construction and infrastructure to underground turbine installation. “The thing is that every piece of ground has its own geology. Our expertise is in understanding how to develop and utilise our products safely and effectively in different locations and at different times,” he says.
Because different locations require different type of support, Normet has developed products that are suited to unstable geologies, providing effective alternatives for any situation to customers. As well as traditional cable bolts, patented dynamic and self-drilling bolts are available that offer superior flexibility. The genius of these patented designs is in their simplicity, Petranek says. “Sometimes, the simplest thing works the best. If you overcomplicate the design of some element of a product, you may not achieve what you wanted to and may actually create a lot of other issues.”
High-strength energy-absorbing ground support
The D-bolt, for example, is an energy-absorbing rock bolting system for use in projects where the rock strata might change unpredictably, such as in areas of increased seismic activity. Change might also be induced by drilling or blasting activity. If the force created is not all absorbed by material destruction, then it is stored in the rock, creating stress. “The D-bolt can absorb rock dilation energy in a way that traditional cable bolts – that have very low deformability – cannot. It stretches, then yields, then can deform again, all while maintaining its strength. This type of high-strength, high-yield steel is the best solution for this type of environment.”
Another tool to make ground support more efficient is self-drilling anchors and bolts. These solutions combine bolt installation and grouting into one process, making the process safer and more efficient. “By drilling in the bolt,” explains Petranek, “you perform the whole installation, which is very different from other techniques where you need to spend a lot of time reboring and recleaning to keep the hole open, especially in unstable conditions.”
As one of the key processes in Normet’s portfolio, ground and rock support is a prime example of how the company’s industry knowledge is levered to support customers. “Through our experience and expertise acquired over many years we are in a position where we can suggest the most effective solutions available on the market to our customers,” Petranek concludes, “for any type of project and environment.”
About the author
Director Products and Production, Rock Reinforcement