Misich, I & Sherwood, R 2008, 'Implications of Recent Mining Subsidence on Infrastructure in the Collie Basin, Western Australia', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 311-324, https://doi.org/10.36487/ACG_repo/808_105
(https://papers.acg.uwa.edu.au/p/808_105_Misich/)
Abstract: Nearly fifty years after mine closure, a sudden collapse of ground above the Stockton Colliery underground workings in the Collie Coalfields resulted in extensive cracking of the ground surface and closure of the gazetted Shotts Road. Investigations determined that the collapse, irregular in shape, covered an area roughly 120 x 120 m and that the depth of mining varied between 20 and 41 m in that location. The mechanism of failure is interpreted to be collapse of columns of sandstone (above coal pillars in the Stockton Colliery workings) that were formed by roof collapse of roadways/drives surrounding the coal pillars. 

The implication of this recent subsidence event is significant to town planning in the Collie region. The likelihood of additional mining subsidence is now much greater than previously expected, particularly above other abandoned underground mines with similar mining/geological environments. Respective stakeholders should take the view that subsidence is likely to develop above each underground mine in the Collie Basin; the impact on the ground surface varying from negligible to severe, depending on local conditions. Any land development proposals that cannot tolerate the expected forms of mining subsidence, or cannot be suitably repaired, should be avoided.