St George, JD 2009, 'Risk assessment for urban development of land subject to ground movements from abandoned old workings', in AB Fourie & M Tibbett (eds), Mine Closure 2009: Proceedings of the Fourth International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 561-568, https://doi.org/10.36487/ACG_repo/908_44
(https://papers.acg.uwa.edu.au/p/908_44_St George/)
Abstract: The presence of old abandoned workings underlying existing residential or planned residential development 
is a problem to land territorial authorities, developers and residents. Where the regulations controlling land 
development are managed on an effects-based approach, the hazards from abandoned underground 
workings present a particular problem to territorial authorities since they have overall control of 
development at any location. This in some way implies the acceptance of these risks and the acceptance of 
liability should anything occur. This paper will focus on the subsidence zone affected by surface intervention 
such as crownholes and the need to define the boundary of this zone in a practical engineering sense. A 
probabilistic framework is used to model the geological and mining uncertainties inherent in this type of 
analysis. The consequences of an event occurring and any remedial action taken are combined with the 
uncertainties to express the outcome in terms of risk. This approach is compared to other natural and man-
made hazards influencing land development.