| Underhand drift cut-fill stoping is widely used in the world due to the maximum recovery of difficulty-mined and deep ore body. Based on the underhand drift horizontal slicing and cut-and fill stoping in the northern part of Wushan copper mine,optimizing the structural parameters of stope and the deformation and breaking of surrounding rock excavation are studied in combination with enginerring geological incestigation , in-situ monitoring, , numerical simulations,similar material simulating test and field monitoring.Main achievement is as follows:(1) The deformation of backfill roof is mainly controlled by cement-sand ratio,In comparison to arrangement ways of reinforcement and Section Specifications,cement-sand ratio is determined the nature of the deformation of backfill roof.(2) Cutting the stope led to the stress distribution and the displacement of backfill roof is much greater than ore floor and sides.(3) The tensile stress of the backfill roof is positively correlated with span.The stress range of the stope corner is positively correlated with the stope height, The greater height, the greater the stress range.Increasing the backfill roof height is good for decreasing the stress concentration.(4) Compared with the backfill roof of 4×3 m2 section , 5×3 m2 section appeare fissures earlier and has more fissures when using cyclic loading and unloading on resembling simulation experiment.In the center of backfill roof and the corner of each side always appears fissures earlier.(5) Horizontal steel tube laying improve the tensile properties of backfill roof, but the existence of horizontal steel tube also aggravate side-fall.(6) The structural parameters of stope in the northern part of Wushan copper mine is recommended by 4m×3m.The above research results further perfect and enrich the theory of cemented backfill mechanics and have important theoretical and engineering application for safe ,efficient and reasonable recovery the underground mineral resources. |
PDF Full Text Request