Sullivan, TD 2020, 'Hydromechanical coupling concepts for mine slopes', in PM Dight (ed.), Slope Stability 2020: Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 65-98, https://doi.org/10.36487/ACG_repo/2025_0.04
(https://papers.acg.uwa.edu.au/p/2025_0.04_Sullivan/)
Abstract: In soil and rock environments, effective management of any excavation is dependent on an understanding of the slope movements and the factors that influence these. Slope movements cover a continuum from small deformations to collapse. These movements are nearly always of sufficient magnitude to affect the physical properties of the rock mass, the groundwater contained therein and the potential impacts from external loading events. Consequently, a thorough understanding of the mechanisms and the roles of stress, creep movements, instability, ground and surface water impacts at each stage of the movement process is fundamental for effective management and control of slopes.
This paper covers the theory and practice with excavated slopes in lower strength materials in some typical geotechnical settings focussed on the roles of ground movements, ground and surface water interaction and hydromechanical coupling. Wide experience has demonstrated there are common behavioural patterns associated with these typical geotechnical settings. The behavioural patterns comprise the processes, interactions and responses; which occur to various degrees throughout most stages of the life of an
excavated slope.
The paper deals with soil and soft rock, footwalls and inclined layered or bedded sequences. However, the same concepts and ideas also apply to various extents to jointed hard rock and complex geological/geotechnical materials. The examples are based on large-scale monitored performance. The paper shows how the geotechnical and hydrogeological character of the materials leads to complex interactions between the various factors. The aim of the paper is to provide practical guidance for professionals working in the mine slope environment.

Keywords: hydromechanical coupling, mine slopes, pit slope movement, in situ stress, groundwater, transient groundwater pressures, geotechnical settings