两中段开采的水平矿柱失稳影响因素分析与方案优化——以金川二矿区为例

Analysis of Factors Influencing Horizontal Pillar Instability and Optimization of Two-level Mining Plans——Taking Jinchuan No. 2 Mine as An Example

为评价两中段开采水平矿柱开采方案的优劣,采用评价水平矿柱稳定性的平均压应力(ASH)、平均剪应力(SSH)和屈服比(FRH)3个指标,并建立数值正交试验方案。通过计算各个试验方案水平矿柱稳定性影响因素的水平、平均值、极差和影响因子,研究各因素对水平矿柱稳定性的影响程度。结果显示:就金川二矿区1号矿体2期工程而言,两中段回采水平矿柱稳定性的主要影响因素有1250中段下降距离、水平地应力、一次回采进路的条数和1250中段的回采方向;维持两中段回采水平矿柱稳定性的关键在于利用水平地应力和调整1 250 m中段的回采工艺、结构参数和开采顺序,而通过提高充填体质量对提高矿柱的稳定性效果并不十分显著。

In order to evaluate mining plans of the two-level mining horizontal pillar, averaging stress of horizontal pillar （ ASH ） , shear stress of horizontal pillar （ SSH ）, and failure ratio of horizontal pillar （FRH） were taken as the evaluation indexes. A numerical orthogonal pilot program was worked out. Effects of factors on the horizontal pillar＇s stability were studied. The results show the main factors affecting the two-level mining horizontal pillar stability are1250 mid-fall distance, horizontal ground stress, the number of mining entrances and the mining direction of 1250 m level, and that the key to two-level mining horizontal pillar stability is using horizontal ground stress and adjusting the 1250 m level mining technology, the stope structure parameters and the mining sequence, but improving the filling body quality is not very helpful in improving the pillar stability. The study is provided with practical reference to the two-level mining horizontal pillar stability evaluation.