Settlement and stability of a coal mine dump using a hypoplastic constitutive model

This paper investigates the present and future stability of an open-cast coal mine dump consisting of a loose, double porous material up to 200 m high. To properly calibrate the constitutive model, unique laboratory samples with a reduced granulometry curve were created and tested. The precision of the calibration was assessed with respect to the measured dump settlement. The stability analysis of the dump was eventually quantified using the strength reduction method for the hypoplastic clay constitutive model and further compared with predictions provided by the Mohr-Coulomb constitutive model. The landfill was found to be stable for both the present and future states using both models. The differences in factors of safety between the both models were ranging from 3% to 8%.