Peng's ground control course examined 16 case studies of ground control failures in North America including pillar failures, roof falls, gutters, roof bolting failures, floor heave, multiple-seam mining and flooding in both longwall and room and pillar mining.

Multiple-seam interactions are major ground control hazards in many US underground coal mines, particularly in Central Appalachia where many worked out mines lie above and below present and future operations.

"In all three sessions, people were very interested in multiple-seam mining," Peng said.

"In Australia, people are getting more serious about that mining situation ... and they also wanted to discuss ground control theory and subsidence.

"Obviously in New South Wales the subsidence issues are pretty serious and in Queensland I have been told there is a growing focus on subsidence."

Peng said all three sessions were filled by mine operators and consultants, with about 70 people attending the three sessions overall.

He said many of the examples and solutions discussed in the workshops could be applied to Australian coal mines.

"There is so much interest in this course because a great majority of the situations I described from US mines are applicable here," Peng said.

"There are some differences in ground control practices [in Australia] but the big issues are still the same."

Peng told ILN he was very impressed by how many geotechnical consultants there are in Australian mines, even though the production is only about one-third of the US tonnage.

"The way the Australian industry is using the geotechnical engineers in design improvement in longwalls is a really good thing and I think the US should do it more," he said.