C.O. Aksoy

Long-term time-dependent consolidation analysis by numerical modelling to determine subsidence effect area induced by longwall top coal caving method

Longwall top coal caving (LTCC) is one of the mining methods used in thick coal seams. Large subsidence occurs over the coal mines, where this method is utilised for production. The area affected by subsidence differs due to varying limit angles of the geological formations in the overburden. However, subsidence does not occur instantly, it is a phenomenon which progresses in time. It is especially important to perform time-dependent analyses of mines in the neighbourhood of residential areas, agricultural zones, or any kind of man-made structures. In this study, the long-term development of a subsidence due to production in an underground coal mine in Manisa-Soma-Eynez was examined using time-dependent numerical modelling technique. 750 days after the end of production, the effects of subsidence were examined in place, measurements were taken from the field and they were compared with the results of the time dependent numerical modelling analyses. [Received: November 15, 2014; Accepted: October 6, 2015]

Safety pillar design for main galleries in multi-slice longwall top coal caving method

Longwall top coal caving (LTCC) is one of the methods used in thick coal seams. In coal mines where this method is used, some coal is left in place to be retrieved later in order to prevent damage to the main galleries. Stresses and strains created by roof layer caving of the panels advancing towards each other may put pressure on the main galleries. The amount of this pressure increases with time-dependent consolidation of roof layers. Sizes of the safety pillars gain importance in order to prevent this pressure and thus avoid the damages on the supports of the main galleries. In this research, great deformations creating damages on the supports of the main galleries of an underground coal mines in Manisa, Soma-Eynez were examined. Time-dependent deformation amounts were investigated both in situ and with time-dependent numerical modelling analysis. The results obtained by this research provide the sizes of the safety pillars in the panels to be produced. [Received: September 24, 2014; Accepted: December 25, 2014]