大冶铁矿同阶段崩落法转充填法开采隔离间柱合理宽度确定

Determination of Reasonable Width of Isolation Pillar between Caving Method and Filling Method in Same Level Mining Areas of Daye Iron Mine

为保障同阶段崩落法转充填法开采顺利过渡,过渡段处须设置竖向隔离间柱。以大冶铁矿龙洞采区-170 m同阶段崩落法转充填法梯形隔离间柱为研究对象,将其简化为变惯性矩固支梁,并以间柱的水平应变量允许值为判据,初步确定梯形隔离间柱上端的初始宽度。以梯形隔离间柱上端的初始宽度为基础,采用数值模拟方法,计算了不同梯形隔离间柱上端宽度与不同充填体灰砂比协同作用下的充填采场顶板围岩沉降量,并对不同灰砂比下梯形隔离间柱上端宽度与顶板围岩最大沉降量进行了数据拟合,由顶板围岩允许沉降值得到与不同充填体灰砂比协同匹配下的梯形隔离间柱上端的合理宽度。数值计算结果表明:与充填体灰砂比分别为1∶4、1∶6、1∶8、1∶10、1∶12协同匹配的梯形隔离间柱上端合理宽度分别为16、19、21、25、29 m。研究成果可为合理确定矿山同阶段崩落法转充填法开采过渡段隔离间柱宽度提供参考。

In order to ensure the smooth transition of mining from caving method to filling method in the same level,a vertical isolation pillar shall be set at the transition section.Taking the trapezoidal isolation pillar of-170 m in Longdong mining area of Daye Iron Mine as the study object,it is simplified as a fixed beam with variable moment of inertia,and the initial width of the upper end of the trapezoidal isolation pillar is preliminarily determined based on the allowable value of horizontal strain of the pillar.Based on the initial width of the upper end of the trapezoidal isolation pillar,numerical simulation method is used to calculate the settlement of roof surrounding rock of the filling stope under the synergistic effect of the different width of upper end of the trapezoidal isolation pillar and the different cement-sand ratio of backfill,and data fitting between the upper end width of the trapezoidal isolation pillar and the maximum settlement of the roof surrounding rock under the different cement-sand ratio is carried out.From the allowable settlement of roof surrounding rock,a reasonable width of the upper end of the trapezoidal isolation pillar was obtained,which was matched with the cement-sand ratio of the backfill.The numerical calculation results show that the reasonable width of the upper end of the trapezoid isolation pillar matching backfill with the cement-sand ratio of 1∶4,1∶6,1∶8,1∶10 and 1∶12 is 16 m,19 m,21 m,25 m and 29 m respectively.The above study results can provide a reference for the determination of reasonable width of the transition isolation pillar in the same horizontal caving method to filling method.