Dynamic Surface Subsidence Characteristics due to Super-Large Working Face in Fragile-Ecological Mining Areas: A Case Study in Shendong Coalfield, China

The dynamic subsidence characteristics due to super-large working face (SLWF) are the basis for further understanding of land ecology damage in fragile-ecological mining areas. In order to acquire the evolution characteristics of dynamic subsidence parameters and surface cracks, a series of field monitoring and comparisons with previous studies were conducted. The results indicate that (1) the subsidence trough is characterized with self-healing characteristics, including rapid formation of subsidence trough, the convergence of deformation, a steep trough edge, the smaller range of surface cracks; (2) the dynamic curves of dynamic subsidence parameters conformed to the exponential function curve with an inflection point when the SLWF advanced ca. critical dimension, which is the commonality of the dynamic subsidence characteristics; and (3) the optimized monitoring strategy for land ecology damage is recommended, and more attention should be paid to the quantitative prediction of root damage due to coal mining. The research results would benefit mining damage control and civil engineering protection in fragile-ecological mining areas.