The instability of mining waste dumps poses significant environmental hazards, including loss of life, damage to infrastructure, and ecological degradation. The complex interdependence of Thermal, Hydraulic, and Mechanical (THM) processes has been increasingly recognised as a critical factor influencing slope stability. In this study, a coupled THM numerical model was developed using the finite element method (FEM) to evaluate slope stability in a coal mine waste dump in Maamba, Zambia. Key parameters, including stress distribution, displacement, pore water pressure, and temperature variations, were incorporated to achieve a comprehensive assessment of slope failure mechanisms. Field data and geotechnical investigations were integrated with advanced computational simulations to ensure realistic modelling. The findings demonstrated that conventional limit equilibrium methods (LEM) underestimated the impact of coupled processes on slope failure. The safety factor was observed to decrease by more than 30% due to THM interactions, with thermal gradients and hydro-mechanical (H-M) responses identified as primary contributors to slope instability. The results underscore the necessity of incorporating THM coupling in slope stability assessments, particularly in geotechnically sensitive mining environments. The proposed framework provides a scientifically grounded methodology for evaluating and mitigating landslide risks in mining waste dumps, offering valuable insights applicable to regions with similar geotechnical and climatic conditions. The findings contribute to the refinement of slope stability management strategies and provide a basis for the development of risk mitigation measures in vulnerable mining areas.

The effects of polycarboxylate superplasticizer (PCE) on the rheological properties and workability of cement-based composites were investigated by testing parameters such as static yield stress, dynamic yield stress, plastic viscosity, slump flow, bleeding rate, and penetration depth. The correlation between the dosage of PCE and the rheological parameters of fresh cement-based composites was analyzed. The results indicated that with an increase in the PCE dosage, the static yield stress, dynamic yield stress, and plastic viscosity of fresh cement-based composites decreased, demonstrating that PCE can improve the rheological properties of these composites. As the PCE dosage increased, the slump flow and bleeding rate of fresh cement-based composites also increased, but the rate of change decreased at higher dosages. Additionally, with an increase in PCE dosage, the penetration depth gradually increased, while the penetration depth difference ($\Delta {H}$) decreased. Furthermore, the compressive strength of cement-based composite cubes slightly decreased with an increase in PCE dosage.