ABSTRACT
Extraction of underground solids causes changes of the initial state of stress in the rock mass and results in ground surface deformation, known as subsidence. The magnitude of the subsidence depends on the geometry of the underground excavation, depth of the mining operation, mining method, mechanical characteristics of the rock mass. The magnitude of subsidence may be determined either from surface monitoring surveys or using empirical or deterministic prediction theories. The goal of the study was to determine direct and residual ground surface subsidence caused by historical coal mining in the Coal Field in Nova Scotia Canada. Direct surface subsidence was calculated using Knothe's empirical model. Long-term subsidence was determined using satellite radar interferometry (SAR). The results of InSAR analysis gave long-term (recent 8 years) subsidence reaching in some places 56 mm. The study showed that long-term subsidence may last even more than 60 years after mining activities.
