Research on support-rock system in solid backfill mining methods

Analyzed support-rock system and overburden movement features in backfill mining,different load estimation formulas which were already verified by engineering examples for the main roof were set up.Studies show that the range of periodic weighting is relatively wide in backfill mining,and the weighting strength is also low;immediate roof will be caving as the advance of the face.The main roof may move to goaf by a slow mode of subsidence,and displacement can dramatically decrease.Higher support working resistance can effectively control roof subsidence at the early stages,not only guarantee the good filling effect,but also decrease the height of slowly subsided zone,as a result,ground surface deformation can be well controlled.