Surface Subsidence Velocity of Fully–Mechanized Thick Seam Top Coal Caving Mining

摘要

Surface subsidence for fully mechanized thick seam top coalcaving was measured, and surface subsidence characteristics werethen analyzed. The subsidence initiation distance from the set-uproom and the advance influence distance ahead of the advancinglongwall face were studied. The maximum surface subsidencevelocity and the delay angle of the maximum subsidence velocitywere determined. The results indicated that surface movementwas intensive, the surface subsidence velocity was very high, theground surface was badly damaged, and the subsidence initiationdistance from the set-up room was smaller than that in generalgeological and mining condition.