Influence of the Mining Method on the Subsidence Movements of the Earth's Surface.

Paper examines conditions prevailing in the Ruhr (West Germany) coal mining region which has a long history of mining exploitation, resulting in the interrelationships of old and recent movements of rock strata in which the subsidence of the surface represents the last phase of movements initiated by the caving-in of the roof strata overlaying the mined-out cavities. Measurements of the movements at the surface (vertical and lateral), as an effect of mining by caving of 2 flat-lying coal seams at the depth of 360 m, 2. 0 and 1. 0 m thick respectively - carried out over a period of time - are given and practical conclusions are drawn.