Queensland’s Julius Kruttschnitt Mineral Research Centre says it is developing a new method of rock bolt safety testing for use in mining and civil engineering that could replace a slow, and often unreliable, method of rock bolt testing used throughout the mining industry.

The JKRockBoltTester’s developer Dr Nenad Djordjevic said properly secured rock bolts influenced safety, particularly in tunnels. "Rock falls are the major cause of fatalities in the mining industry, and the lack of, or improper bolting can contribute to these incidents," he said.

The new rock bolt testing method would be "non-destructive" as there was no need to pull out bolts installed inside mines or similar places to check whether they needed replacing.

"The rock bolt tester could lead to improved rock bolting practices as current rock bolting is sometimes excessive because it is not measurement-based," Dr Djordjevic said. "Currently, the only way to test rock bolts is the pull-out test, which is not routinely used in practice due to its destructive nature."

Dr Djordjevic is adapting an ultrasonic detection method for checking each bolt fixed inside the rock based on the measurement of the "frequency response function". The new method means maintenance crews would only need to "listen" to the bolt to determine whether replacement was necessary. With such a method at hand, it would take only minutes to test each bolt, marking them electronically and ranking the order of maintenance or replacement required. "It means hundreds of bolts can be tested in a matter of hours, whereas, the pull-out method could mean hours of work for each bolt," Dr Djordjevic said.

ANI is supporting the early stages of the research with the supply of rock bolts for JKMRC tests currently underway at the University of Queensland’s experimental mine in Brisbane.

ANI Strata Products research and development manager Mietek Rataj said even though Australian roofbolting technology was well developed there was some room for improving installation techniques. "The major advantage from this research could be the assessment of the quality of a bolt encapsulation," he said.

Rataj also saw an application for the rock bolt tester in civil engineering as well as mining.

Dr Djordjevic said development of a prototype rock bolt tester would continue until mid-2000. During this time, research would focus on bolt conditions, including varying bolt lengths and grout quality. He said the rock bolt tester would initially be developed for hard rock mines, but he predicted significant demand from the coal industry, the largest user of rock bolts in Australia.

Given the importance of fast-tracking the project to enhance minesite and public safety, Dr Djordjevic said he was keen to hear from organisations wishing to help develop the rock bolt tester for industrial use by the end of 2000.