Mining subsidence engineering

If large, continuous cavities are created underground, as for example in coal mining, the layers of rock over the deposit generally break and subside. The subsidence can be reduced in amount and severity by filling in, or “stowing,” the mine cavity with waste material. In the course of subsiding, the land surface deforms into a generally flat, plate-shaped trough, the edge of which travels ahead of the mine working. The effects of mining may simultaneously cause a structure to subside, tilt, bend, and be extended or compressed, with extension and compression sometimes alternating. Areas turned into swamp or placed permanently under groundwater have to be kept drained.