Analysis and Prognosis of Surface Subsidence in the Jiu Valley

Surface subsidence resulting from underground mining activities is a critical environmental and engineering concern that has garnered substantial attention in both academic and practical contexts. The phenomenon occurs when the removal of underground materials, such as coal, minerals, or ores, leads to the collapse or settling of the surface. This study examines mining operations conducted within the thick coal seams of the Jiu Valley Coal Basin in Romania, which utilize longwall mining techniques featuring roof control through caving or top coal caving methods. The analysis focuses on the complex deformations of the ground surface that have occurred over time as a direct result of coal extraction activities in specific mining sectors of the basin. Furthermore, the phenomenon of ground surface subsidence is investigated using the CESAR-LCPC finite element code. The modeling is conducted under the assumptions of elastic and elasto-plastic behavior. A temporal analysis of ground surface deformation is also conducted using a profile function. The results obtained from the modeling are subsequently compared with a comprehensive dataset of in situ measurements.