Assessing the geotechnical susceptibility of caves in Pilbara iron formations to instability

Natural caves are common features of the iron formation strike ridges in the topography of the Pilbara Region of Western Australia, which are also host to many of Australia’s major iron ore deposits. These caves are increasingly being recognised for their ecological and heritage value. Consequently, there is an emphasis on preserving the structural integrity and minimising potential impacts caused by nearby mining activities, while also reducing risk to personnel undertaking research or monitoring activities within the caves.

The morphology and engineering geology of the Pilbara iron formation caves are central to understanding potential failure mechanisms and triggers to rockfall in the caves. A methodology has been developed for assessing geotechnical susceptibility of the caves to instability, which is used to inform risk and impact assessments for nearby mine developments. The approach uses detailed engineering geological observations to identify susceptible features and potential hazards to personnel working in and around the caves as part of ecological and heritage monitoring.