大红山铁矿深井大规模开采岩爆综合评价

大红山铁矿是特大型深埋矿床,在深井开采时遇到的一个技术难题就是岩爆。为评价岩爆倾向性烈度,对该矿深部5种岩样进行室内岩爆倾向性试验,并采用声发射方法确定岩石接近峰值强度时的卸载点;通过地应力现场实测和三维有限元数值模拟,获得深部最大主应力和巷道开挖后最大切向应力;采用最大主应力判别法、切向应力准则、强度脆性系数法、变形脆性系数法、弹性应变能储存指数法这5种评价方法,对岩样的岩爆倾向性进行单项指标评价,分别得到各矿岩岩爆倾向性烈度。然后采用模糊数学法,对各单项指标评价结果进行综合评价。结果表明:深部主要矿岩体总体上具有发生中等岩爆和强烈岩爆的倾向性。最后,通过评价结果,在岩层图上绘制典型水平岩爆倾向性分布区域,可为深部开采和岩爆防治提供参考依据。

Comprehensive Evaluation of Rockburst on Deep and Large-scale Miming in Dahongshan Iron Mine

Dahongshan iron mine is oversize and deep-buried deposit，and a technical problem that must be faced in deep mining is rockburst.To evaluate the intensity of rockburst proneness，indoor rockburst pronenss experiments of five kinds of rock samples from deep mine are recorded，and acoustic emission is used to control the unloading point near to peak strength of rock；According to the ground stress measured in field and result of three-dimensional finite element numerical analog，maximum primary stress in deep mine and tangential stress values after tunnel excavation are obtained.Five judging methods of maximum primary stress criterion，tangential stress criterion，strength brittleness coefficient method，deformation brittleness coefficient method and elastic strain energy storage index method are used to make an estimation of one index about rockburst proneness，and rockburst proneness intensity of rocks in Dahongshan iron mine is obtained；Then，the method of fuzzy mathematics is used to make an integrated evaluation.The result shows that there is medium and strong rockburst proneness of main rocks in deep mining.At last，distribution map of rockburst proneness in typical level is plotted according to the evaluation result，which provides reference for mining and rockburst control in deep mining.