Mine subsidence can take the form of sinkholes or troughs depending on mining and geologic conditions. Examples of the geology, mining, and subsidence features encountered in core and on the surface from US Bituminous Coal fields, particularly in the widely mined Pittsburgh Coal Seam; the Anthracite Coal field of north-eastern Pennsylvania; and the Sydney Basin, particularly the Borehole Seam, will be illustrated. The importance of understanding the mining and geology with respect to expected subsidence conditions and interpretation of investigation results will be stressed. Guidance on sinkhole development criteria and trough subsidence deformations will be provided. Finally mitigation options, such as grouting will be reviewed.
Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.