The one-day workshop is intended for mine planners and site personnel involved in the formulation and day to day management of mine site strata control, including mining engineers, geologists and mine management.

The workshops will be run by leading geotech consultancy, Strata Engineering which conducted two of the projects and was involved in the third. They are being held on October 21 in Belmont, NSW, October 23 in Penrith, NSW and October 28 Moranbah, QLD

David Hill will speak on Pillar Design and behaviour (i.e. appropriate stability criteria), as well as the outcomes of recent industry experiences.

Hill will describe recent innovations in chain pillar design (eg splay pillars) and monitoring. Also, work will be presented that has combined both Factor of Safety and width:height ratio into an integrated pillar stability condition, using failed pillar databases from Australia, South Africa and elsewhere. It allows pillars to be designed with a lower overall Factor of Safety without compromising stability, the result

being less roadway drivage.

Paul Buddery will describe investigations into two types of grouting in coal mines: cementitious and PUR grouting.

The PUR component of the research involved a number of underground case studies and trials which have led to modified thinking on the mode of action of PUR and the most cost-effective means of applying it.

The cementitious grouting component primarily involved a review of the state-of-the-art of similar grouting techniques in the civil engineering industry where they are used more extensively than in coal mining. The relevance of civil engineering practice was assessed in the light of coal mining needs and a guideline developed for improving industry practice.

Steven Ditton talks on research into Subsidence Impact Prediction.

Mine subsidence prediction above longwall panels is still yielding unexpected outcomes in the Newcastle Coalfield due to (i) the presence of massive conglomerate and sandstone channel lithologies, (ii) the deeper panel geometries that are now being extracted, and (iii) chain pillar compression effects.

This session covers the empirically based methodology developed to assess lithological and geometrical variation effects, associated basic overburden behaviour conceptual models, subsidence over chain pillars, the prediction of strain, tilt and curvature (beyond ‘smooth’ profiles) and the height of sub-surface fracturing above a

longwall panel for the assessment of groundwater impacts.

Further enquiries please direct to Strata Engineering, (02) 49588477 or e-mail engstrat@ozemail.com.au.