Characterising the multi-seam subsidence due to varying mining configuration, insights from physical modelling

Multi-seam mining-induced subsidence profile is observed to be different from that of single-seam mining. Understanding the characteristics of multi-seam subsidence is the first step in achieving reliable subsidence predictions. Characteristics of multi-seam subsidence are investigated by means of several sand-plaster physical models. Geological and site specific parameters are kept constant in all the models in order to compare the multi-seam subsidence parameters for different mining configurations. Based on observations from the physical models, it is concluded that the panel configurations of the two seams have significant impact on the multi-seam subsidence development. Based on the relative location of the panels the multi-seam mine area can be divided into different zones, to which suitable subsidence characteristics can be assigned. Dividing the mine area into different zones enables characterisation of the strata movement and multi-seam subsidence for various multi-seam configurations. The proposed characterisation of the multi-seam subsidence can also be utilised in subsidence prediction methods in order to achieve reliable prediction results.