佛子矿间柱回收与空区稳定性数值模拟

Study on Spacer Pillar Stoping and Goaf Stability Numerical Simulation of Fozi Mine

佛子矿长期采用浅孔留矿法回采矿体,在矿体上部残留有大量未回收间柱,该矿拟回收104号矿体138m中段的部分间柱。结合现场实际情况,采用有限差分软件FLAC3D对开采现状及抽柱法、削柱法2种间柱回收方案进行模拟研究。其中,对开采现状的模拟表明,138 m中段间柱和采空区顶底板的应力值均小于该中段矿岩体的破坏强度,说明该中段暂时处于稳定状态,可以进行矿柱回收。对抽柱法和削柱法回收间柱进行模拟表明,间柱回收后,区域内的应力值较回收前有一定的增长,但削柱法回采下的最大压应力和最大拉应力增幅均小于抽柱法,说明削柱法方案优于抽柱法方案;削柱法回采间柱后,该中段的应力值已接近矿岩体的破坏强度,应在回采完毕后,对残余矿柱进行加固处理。

Fozi Mine used short-hole shrinkage method to mine, a lot of parital spacer pillars were left in the upper part of the ore-body. Fozi Mine intends to recycle the pari tal spacer pillar of 138 m level middle section of 104 ore body. Combined with the actual situation, this paper simulates of current mining situation, recycling the second spacer pillar and recycling half of every spacer pillar by finite difference software FLAC3D？ The simulate of current mining situation shows that the spacer pillar, roof and floor stress are less than the ore rock mass strength value, it means that 138 m level middle section is stable and the pari tal spacer pillar can be recycled. The simulates of recycling the second spacer pillar and recycling half of every spacer pillar shows that the stress value of area have a certain growth after recycling the spacer pillar, but the the maximum principal stress and minimum principal stress increment of recycling half of every spacer pillar is less than recycling the second spacer pillar, it means that recycling half of every spacer pillar is better. The stress value of 138 m level middle section is close to the ore rock mass strength value after recycling half of every spacer pillar, we should reinforce for residual pillar.