开挖扰动下矿柱损伤破裂失稳细观机制研究
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摘要
为揭示开挖扰动下矿柱损伤破裂失稳的细观机制,以盘龙铅锌矿采场间柱破裂为原型,运用PFC~(2D)对其破坏机理进行反演分析,建立基于声发射累计数的尖点突变失稳判别模型。研究结果表明:采空区上方形成压力拱,拱内岩体自重转移到附近围岩和矿柱,产生应力集中;矿柱受压逐渐产生损伤,其损伤破裂失稳演化过程分为3个阶段:弹性阶段、屈服阶段、失效阶段;矿柱内部以拉裂纹为主,细观破坏形式主要为拉伸破坏,宏观表现为剪切滑移破坏。经验证,基于声发射累计数的尖点突变模型能够有效判别矿柱失稳状态。
In order to reveal the meso-mechanism of the pillar damage and failure caused by excavation disturbance, PFC~(2D) was adopted for the inverse analysis of the failure mechanism for Panlong Lead-Zinc Mine with the interval pillars in the stope mining. And a cusp catastrophic model for instability detection was established based on the cumulative number of acoustic emissions. The results showed that the pressure arch was formed above the goaf, and the weight of rock mass in the arch was transferred to the surrounding rock and pillar, resulting in the concentrated stress. The pillar was gradually damaged under pressure, with the damage and fracture evolution process divided into three phases: elastic phase, yielding phase and failure phase. The tensile crack was the predominant failure in the pillar, with tensile failure as the predominant mesoscopic failure mode and the shear slip failure as the macroscopic performance. It was verified that the cusp catastrophe model based on the cumulative number of acoustic emission could effectively determine the instability of the pillar.
In order to reveal the meso-mechanism of the pillar damage and failure caused by excavation disturbance, PFC~(2D) was adopted for the inverse analysis of the failure mechanism for Panlong Lead-Zinc Mine with the interval pillars in the stope mining. And a cusp catastrophic model for instability detection was established based on the cumulative number of acoustic emissions. The results showed that the pressure arch was formed above the goaf, and the weight of rock mass in the arch was transferred to the surrounding rock and pillar, resulting in the concentrated stress. The pillar was gradually damaged under pressure, with the damage and fracture evolution process divided into three phases: elastic phase, yielding phase and failure phase. The tensile crack was the predominant failure in the pillar, with tensile failure as the predominant mesoscopic failure mode and the shear slip failure as the macroscopic performance. It was verified that the cusp catastrophe model based on the cumulative number of acoustic emission could effectively determine the instability of the pillar.
引文
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[10] 广西中金岭南矿业有限责任公司,中南大学.盘龙铅锌矿地压控制智能化综合监控技术研究(第1阶段)[R].2016.
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[2] 徐文彬,宋卫东,杜建华,等.崩落法转阶段嗣后充填法采场稳定性分析[J].工程科学学报,2013,35(4):415-422.
[3] 曹帅,杜翠凤,谭玉叶,等.金属矿山阶段嗣后充填胶结充填体矿柱力学模型分析[J].岩土力学,2015,36(8):2370-2376.
[4] Zhi-guo Huang,Xing-guo Dai,Long-jun Dong.Buckling failures of reserved thin pillars under the combined action of in-plane and lateral hydrostatic compressive forces[J].Computers and Geotechnics,2017(87):128-138.
[5] 谢学斌,邓融宁,董宪久,等.基于突变和流变理论的采空区群系统稳定性[J].岩土力学,2018,39(6):1001-1011.
[6] 罗辉,杨仕教,陶干强,等.基于FEM-ANN-MCS动态模糊可靠度的矿柱稳定性分析[J].煤炭学报,2010,35(4):551-554.
[7] 姜立春,魏叙深,吴爱祥.基于动态强度折减法矿柱渐进失稳演变规律[J].中南大学学报(自然科学版),2016(2):621-627.
[8] Li X,Konietzky H.Simulation of time-dependent crack growth in brittle rocks under constant loading conditions[J].Engineering Fracture Mechanics,2014,119(3):53-65.
[9] 施耀斌,叶义成,王其虎,等.缓倾斜多层矿床条带法开采矿柱变形特征及开采强度模拟[J].矿冶工程,2015,35(5):4-9.
[10] 广西中金岭南矿业有限责任公司,中南大学.盘龙铅锌矿地压控制智能化综合监控技术研究(第1阶段)[R].2016.
[11] Potyondy D O,Cundall P A.A bonded-particle model for rock[J].International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1329-1364.