Influence of Drift Spacing on Mechanical Behavior and Deformation of Surrounding Rocks in Stope
Increasing the drift spacing of non-pillar sublevel caving method is beneficial to increase the ore amount of primary caving and improve the ore drawing effect.Based on the optimization scheme of the structural parameters of non-pillar sublevel caving method in a certain mine,the stress distribution characteristics,displacement variation and plastic zone distribution laws of the surrounding rocks of the drift were studied with the numerical simulation method under 5 kinds of drift spacing,and the influence of drift spacing variation on the stability of the surrounding rocks was analyzed.The results are concluded as follows.Firstly,under different drift spacing,the maximum principal stress in the surrounding rocks of roof and both sides of the drift show the characteristic that the greater the drift spacing,the smaller the principal stress value.However,as the depth of the surrounding rocks changes,the maximum principal stress shows different changing trends.Secondly,the minimum principal stress of the surrounding rocks of the roof and the sides increases first and then tends to be stable.The maximum principal stress is mainly distributed in the 4-10 m range of the side surrounding rocks of the drift.The smaller the drift spacing,the mutual influence of the adjacent drifts causes stress superposition,which is easy to cause tension failure.The larger the spacing,the smaller the minimum principal stress.Thirdly,the displacement in the surrounding rocks of the roof and the sides presents a change law of"large in the middle and small at both ends".Increasing the drift spacing has a great influence on the displacement distribution area and range of the roof surrounding rocks,but it is beneficial to reduce the mutual influence between adjacent drifts and maintain the overall stability of the drift surrounding rocks.Finally,the plastic zones of drift surrounding rocks are mainly shear plastic zone,which are mainly distributed within 2 m around the drift,and the change of drift spacing has little influence on the expansion of the plastic zone.
Non-pillar sublevel caving methodDrift spacingStress distributionDisplacementPlastic zone distribution
万方数据
维普
