Study of Surface Movement Principle of Coal Seam Mining under Super Thick Unconsolidated Stratum

In order to study influence that mining under super thick unconsolidated stratum to surface subsidence，it taking surface movement observation data of Zhaojiazhai coal mine as base，the influence that mining to surface subsidence characters，the maximal subsidence speed of surface ，delay distance of the maximal subsidence speed of surface and surface movement time in different stage under super thick unconsolidated stratum geological mining situation，the results showed that mining under super thick unconsolidated stratum，surface subsidence index was larger，it almost equal to one，the tangent value was smaller of the main influence angle，surface movement scope larger，offset distance of inflection point was smaller，delay distance of the maximal surface subsidence speed was smaller，then the following conclusions obtained，mining under super thick unconsolidated，surface subsidence speed accelerate，active period prolonged and recession period shorten，residual deformation of surface became smaller and stable quickly，and so on.