Similar material and numerical simulation of strata movement laws with long wall fully mechanized gangue backfilling

This paper studies on strata and surface movement laws with long wall fully mechanized gangue backfilling technology by similar material simulation and numerical simulation method. The results indicate that 1) the overlying strata under the situation of mining with long wall fully mechanized gangue backfilling mainly shows a slow bending and subsidence, characterized by bending, fracturing, and bed separating, while the overlying strata develops fractured zone and bending zone only; and 2) if the compression rate of backfill is about 30%, the surface subsidence coefficient is around 0.22. In addition, this paper points out that improving the filling rate of gangue backfilling in goaf and the initial density of filling body are the main technological way to enhance the controlling effect of strata movement. Based on this point of view, four technical measures are proposed at the end.