According to the backfill mining method, the HSRS is in the most dangerous situation when the mined out rooms have been cemented backfilled
, and the innermost room is a goaf.
The gangue backfilled
GER has the characteristics of fast stabilization, less roadway deformation, no fracture of main roof strata, nonpronounced strata pressure behavior, and less ground subsidence when compared to the GER technology in a roof managed by the caving method.
This section was then completely backfilled
with cuttable, low-density concrete.
The successful cut-through of 3 Right recovery entry can be mainly attributed to the: (1) completely backfilled
low-density concrete, and (2) preinstalled primary and supplemental bolts, along with a T3 roof channel, and steel and nonmetallic recovery meshes, fiberglass bolts in the inby pillar, steel rib bolts in the outby pillar, and angled roof/rib channel.
(2) Checking preparation: the on-off state of the backfilling pipe switches is checked and a report is sent to the backfilling stations, confirming whether or not the area should be backfilled
The preparation and mining of higher lying levels, was conducted successively after the lower level was backfilled
and works had begun on a higher level.
However, all the tailings produced cannot be backfilled
due to the different densities of in situ and broken rock.
The excavation was then backfilled
and compacted in lifts with a pneumatic compactor.
 used the SIGMA/W finite element code to simulate the characteristics of the rock-backfill interface influence on the magnitude of the stresses in backfilled