Dynamic subsidence basins in coal mines based on rock mass rheological theory

Abstract

In order to investigate the surface deformation caused by coal mining and to reduce environmental damage, more accurate information of dynamic subsidence basins, caused by coal mining, is needed. Based on rheological theory, we discuss surface deformation mechanism of dynamic subsidence on the assumption that both the roof and the coal seam are visco-elastic media, put forward the idea that the principle of surface deformation is similar to that of roofs, except for their parameters. Therefore, a surface deformation equation can be obtained, given the equation of the roof deformation derived from using a H|M rheological model. In the end, we apply the equation of surface deformation as a practical subsidence prediction in a coal mine. Given the rheologic properties of a rock mass, the results of our research of a dynamic subsidence basin can predict the development of surface deformation as a function of time, which is more important than the ultimate subsidence itself. The results indicate that using rheological theory to calculate the deformation of a dynamic subsidence basin is suitable and provides some reference for surface deformation of dynamic subsidence basins.