拉拉铜矿落凼矿区深部地应力场特征及岩爆预测分析

Characteristics of in-situ stress field and prediction of rock burst in deep area of Luodang in Lala copper mine

拉拉铜矿位于川滇应力区中部,浅部资源接近开采结束,逐步由露天开采全面转为地下开采,由于其深部开采地质条件复杂,落凼深部矿区将面对开采过程中的地应力问题。以拉拉铜矿落凼矿区深部地应力场特征为研究对象,开展了10个钻孔的应力解除法地应力测试、22组围岩室内物理力学测试,结合国标法、Barton法及陶振宇法3种应力判据完成了深部开采区域的岩爆预测分析。结果表明:地应力值浅部离散分布,深部线性增长;最大主应力方向整体离散;岩爆程度随深度逐渐增大,浅部离散分布,深部逐渐集中,东区1 780 m标高可能出现强烈岩爆的现象;结合矿区断层及测试点分布特征,指出矿区断层及地层对地应力测试结果的影响,为该类金属矿山深部灾害预防及安全开采提供有益的参考。

Lala copper mine is located in the Sichuan-Yunnan stress zone.Since the shallow resources are close to the end of mining,it has gradually changed from open-pit mining to underground mining.Due to the complex geological conditions of deep mining,the deep mining area of Luodang will face the problem of in-situ stress in the mining process.The characteristics of the deep in-situ stress field in the Luodang mining area of the Lala Copper mine were taken as the research object,the in-situ stress tests of 10 boreholes by stress relief method,and 22 groups of indoor physical and mechanical tests of surrounding rocks were carried out.The rock burst prediction analysis of the deep mining area was completed by 3 stress criteria of the national standard method,Barton method and the Tao Zhenyu method.The results show that the in-situ stress was distributed discreetly in the shallow part and increased linearly in the deep part.The direction of maximum principal stress is discrete.The degree of rockburst increases gradually with the depth,distributed discretely in the shallow part and gradually concentrated in the deep part.The phenomenon of a strong rockburst may occur at the elevation of 1780m in the east area.Combined with the distribution characteristics of faults and test points in the mining area,the influence of faults and stratum on the in-situ stress test results is pointed out.It can provide a useful reference for deep disaster prevention and safe mining of similar metal mines.