Advancing the determination and numerical integration of shrink/swell characteristics for the prediction of subsidence and rebound of land

Advancing the determination and numerical integration of shrink/swell characteristics for the prediction
of subsidence and rebound of land

Project Outline

Rehabilitation of the Latrobe Valley open cut coal pits will eventually lead to a refilling of the mine voids with water and advancing the natural process of a rise of the groundwater to levels similar to pre-mining. During the mining process, the aquifers had to be de-pressurised leading to subsidence in the vicinity of the mine pit but also causing a cone of depression. The cause of subsidence is a combination of consolidation processes and shrinkage as a consequence of water loss. Re-pressurisation will lead to swelling and upheave of the subsided land. The extent of swelling is governed by the combination of the extent of drying achieved over time and during the previous de-pressurisation, the geomechanical properties of the individual geological strata affected by the desiccation and the overburden stresses in the soil.

The anticipated PhD project will investigate the extent of the swell/shrink behaviour of land adjoining open cut coal pits using novel experimental and numerical approaches like exploring linkages between hydrological and geomechanical properties as affected by depressurisation or rewetting. The PhD project will apply this information to improve numerical modelling and simulation of subsidence behaviour of various geological substrates and subsequent swelling potential by combining geomechanical data with hydrological information from the site and region.

Supervision team

Professor Thomas Baumgartl, A/Prof Ean Ooi Tat, Dr. Javad Yaghoubi (Research Fellow)