Mercer, KG & Stacey, TR 2008, 'A Generalised Time and Event Dependent Deformation Model for Unsupported Rock Slopes', 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. 481-492, https://doi.org/10.36487/ACG_repo/808_102 (https://papers.acg.uwa.edu.au/p/808_102_Mercer/) Abstract: Deformation has long been recognised as one of the most important parameters which define the state of rock masses. Deformational behaviour of excavated slopes and failures can be extremely complicated and, up to now, there have been no methods or models that have adequately addressed the range of behaviour that is possible during excavation of rock slopes in different geological environments. A new time and event dependent deformation model has been developed to describe how deformation behaviour of excavated rock mass may be presented using deformation pathways. The model accommodates five principal stages of deformation ranging from primary and secondary rock mass creep modes through the onset-of-failure to collapse and post collapse or post mining recovery deformation behaviour. Key features of the new model are the provision of two different stages of event induced deformation behaviour prior to the onset-of-failure. The first stage encompasses relatively uniform deformation rate patterns and the second stage encompasses changing deformation rate patterns as a result of changing deformation rate recovery functions. The provision of changing deformation rate decay functions as a slope progresses towards failure. A description of deformation behaviour which is largely independent of the resulting slope failure mechanism and a description of the inter-relationship between vertical and horizontal deformation behaviour.