程潮铁矿岩爆倾向性分析及其能量预测

Rockburst tendency analysis and its energy prediction in Chengchao Iron Mine

根据系统的工程地质调查,在对井下-430～-568m范围内岩样进行力学实验研究的基础上,采用RMR岩体分类方法和高地应力条件下适应性较好的Q系统,对深部围岩进行了工程分类,并分析了RMR、RQD与岩爆的关系.认为程潮铁矿深部(-500m以下)岩体发生岩爆的可能性较大.通过对矿区地应力分布规律的研究,探讨了矿区高应力环境对岩爆孕育的影响.最后,通过对矿区采场三维有限元数值模拟,分析了深部开采矿岩能量分布规律,据此推断该矿岩爆临界深度在-500m水平.从模拟结果可以看出:地应力环境受上部开采活动的影响,-500m水平应力明显增加,高于-533m水平;-533m水平以下,随着垂直深度增加,矿岩能量最大值逐渐增大.

According to the results of systematical engineering geological surveys, based on the rock mechanical experiment of specimens from - 430 m level to - 568 m level, the Q system which is well applicable to high geostress conditions and the RMR method were applied to rock engineering classification. The relation of rockbursts to the values of RMR and RQD was analyzed. It is known that there is the probability of rockbursts below - 500 m level in Chengchao Iron Mine. The influence of high geostress environment on rockburst preparation was discussed by studying geostress distribution laws. Finally, the distribution state of energy in surrounding rockmass during deep mining excavation was studied by 3D FEM numerical analysis, and it is inferred that the critical depth of rockbursts is - 500 m. On the base of simulation results, the in-situ stress strengthens significantly at - 500 m level due to the impact of upper mining activities, higher than at - 533 m level. Below - 533m level, the maximum value of rockmass energy also progressively increase with the incremental vertical depth.