Optimization of Stope Structure Parameters Under the Condition of Roof Anchoring Support
The structure parameters of the stope directly affect the stability and technical and economic indexex of the stope.The ZnV3 ore body of Jinchanghe Mine in Yunnan Province is mined by stage open stoping with subsequent filling mining method,and the broken surrounding rock of the roof is collaborative supported by prestressed"anchor bolt-anchor cable-anchor net".In order to further improve the production capacity of the stope,the structure parameters of the Ⅱ-step stope were optimized.Based on the thin plate theory,the expression of the maximum tensile stress under the condition of three-sided simply support and one-sided fixed support on the roof of the mine room in Ⅱ-step was derived.Combined with the collaborative supporting mechanism,under the maximum span of 18 m,the tensile stress values of the center of the roof in the x,y directions and the midpoint of the fixed edge are 0.48 MPa,0.21 MPa and 0.55 MPa,respectively,which meet the requirements of roof stability.FLAC3D software was used to construct the stope support model and simulate the calculation.The simulation results show that the minimum principal stress value of the roof is generally distributed between-0.5 MPa and 0.5 MPa under the action of the span reduction of the anchor cable,which is basically consistent with the theoretical calculation results.It is determined that the 18 m span is the optimal span of the Ⅱ-step stope.Compared with the original scheme with a span of 15 m,the loss rate and dilution rate of the optimized scheme with a span of 18 m increases by 1.557％and 0.433％respectively,and the mining-cutting ratio decreases by 1.16 m/kt,which further improves the production capacity of the stope.The industrial test was carried out according to the optimization scheme.Under the span of 18 m,the stope loss rate,dilution rate and mining-cutting ratio are 12.4％,10.8％and 5.7 m/kt,respectively.The roof of the mine room remain stable,which verifies the feasibility of the optimization scheme.The research results can provide reference for similar mines.
Stage open stoping with subsequent filling mining method"Anchor bolt-anchor cable-anchor net"collaborative supportThin plate theoryStope structure parameterTechnical and economic index
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