Optimization and Application of Mining Approach Width in Zhongguan Iron Mine
Reasonable approach width plays an important role in achieving safe and efficient production in deep stopes mined by fill mining method.Numerical analysis method was used to analyze the stress distribution law,displacement change and plastic zone distribution characteristics of surrounding rocks under 5 groups of approach width in Zhongguan Iron Mine.The influence of approach width on the stability of surrounding rocks was studied,and the optimal approach width was selected and verified by field practice.The results show that the tensile stress concentration area of the roof and floor is distributed in the shape of a hump,and the stress value is positively correlated with the distance from the roof of the approach.The compressive stress concentration area of the side wall is distributed to both sides in the shape of a fan arc,the stress value first rises and then falls,the stress peak occurs at 1 m from the side wall,and the possibility of damage to the surrounding rocks is very great.The amount of roof subsidence is in a concave symmetrical pattern of"big in the middle and small on both sides",and the amount of roof subsidence and its increase is much larger than the displacement and increase of the side wall,so the continues increase in the approach width is prone to cause roof collapse accidents.The plastic zone shows a left-right symmetric distribution in morphology and increases in volume with the increase of the approach width,and the volume increase is significantly increased when the approach width is larger than 6 m.The field practice shows that the stability of surrounding rocks in 8N3 stope with 6 m approach width is good,the recovery rate is 93％,the dilution rate is 13％,and the production capacity is 1 400 t/d,with a good application effect.
Approach widthStability of the surrounding rockStress distributionDisplacementDistribution of plastic zone
万方数据
维普
