Influence of Caving Distances on the Stability of Surrounding Rock of Mining Drift
In order to reveal the influence of caving distances on the stability of surrounding rock of mining drift during mining with non-pillar sublevel caving method,an iron mine in Liaoning Province was taken as the research example.Under the existing mining structure parameters of this mine,five different caving distances were set,and numerical simulation methods were used to study the displacement and plastic zone distribution of the surrounding rock after the caving.After the ore caving at different caving distances,the surrounding rock of the drift was in a state of compressive stress,and as the distance from the end wall increases,the maximum principal stresses and minimum principal stresses showed a trend of first increasing and then decreasing.The maximum principal stress reached its maximum value at a distance of 2 meters from the end wall,while the minimum principal stress reaches its maximum value within a range of 4-5 meters from the end wall.Increasing the caving distances was beneficial for improving the stress state of the surrounding rock in the drift.After caving the ore at different caving distances,a"butterfly shaped"displacement area was formed on both sides and arch shoulders of the drift,and a"sinking"displacement area was formed at the top of the drift.Increasing the caving distance resulted in a slight increase in the displacement of surrounding rock,but improved the distribution characteristics of displacement and narrowed the range of displacement.After caving the ore body,the plastic zone inside the surrounding rock was mainly as shear plastic zone,and the distribution range of tensile plastic zone was very small.After increasing the caving distance,the volume of the shear plastic zone and its increase are much larger than those of the tensile plastic zone,and the surrounding rock was prone to shear failure.
Non-pillar sublevel caving methodCaving distanceMining driftStress distributionDisplacementPlastic zone distribution
万方数据
维普
