For the same cement-sand ratio, the tensile failure range of the stope structure gradually decreases and no obvious penetration of the pillar is observed with the increase in the
backfill concentration.
Liu, "Transportability and pressure drop of fresh cemented coal gangue-fly ash
backfill slurry in pipe loop," Powder Technology, vol.
The rheological property is sensitive to the variation of
backfill slurry concentration.
According to the literature [25], it is assumed that the stiffness of normal springs can be equivalent to the coefficient of a subgrade reaction of the
backfill and that the stiffness of the tangential springs is a function of the stiffness of normal springs.
Therefore, to account for stress from external
backfill, a 10-mm annular plate is usually selected.
Paste
backfill mining technology, first proposed by China University of Mining and Technology, is regarded as an important component, having been successfully implemented in the first paste
backfill mining demonstration experiment.
One joint of a gasket pipe was tested with bulkhead installed on each side for water tightness without
backfill.
Backfill Specialists, with an annual turnover of some EUR18m (USD23.3m), provides technical consulting and engineering services, focusing on mine backfilling technologies.
The deepest shaft which is now entirely closed with concrete
backfill, reached a depth of 420 m at approx.
If the
backfill is not adequate, the screw output will be unstable and even the smallest variation in output entering the discharge section will cause the screw to vary in its fill length.
If it is too deep,
backfill with soil, not compost, and firm well, or it will tend to sink.
