断层冲击地压发生机理研究
Research on Mechanism of Fault Rock Burst
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摘要: 为得到断层冲击地压的发生机理,以义马矿区F16断层为研究对象,采用相似模拟和数值模拟的研究手段,研究了开采扰动诱发断层冲击地压的过程,提出了断层滑移失稳的敏感性指标,揭示了断层冲击地压发生的原因。结果表明:按照开采扰动程度的不同将断层冲击地压的过程划分为3个阶段:断层开始活化、断层剧烈活化和断层冲击显现。剪应力和正应力比值作为断层滑移失稳的敏感性指标,可以建立断层应力场和断层活动状态之间的联系;当应力比降低时,滑移速度较小,几乎为0;当应力比开始升高时,滑移速度出现波动并逐渐增大;当应力比达到最大值时,断层滑移速度突变,断层滑移失稳,断层冲击地压发生。采动引起覆岩破坏是断层冲击地压发生的直接原因,开采扰动导致断层应力场改变是冲击地压发生的根本原因。Abstract: In order to obtain the mechanism of fault rock burst occurred, taking F16 fault in Yima mining area as a study object, this paper used analog simulation a nd numerical simulation method. The process of fault rock burst induced by mining disturbance was researched and a sensitivity index of fault slip was proposed. The r eason of fault rock burst was revealed. The results showed that according to mining disturbance degree, fault rock burst contains three stages which were start of fault activation, fault intense activation and fault impact. The ratio of shear stress and normal stress could connect fault stress field and fault activity, the ratio was sensitive i ndicator of fawt slip instabilty.When the stress ratio was low, sliding velocity was almost zero. When the ratio rised, sliding speed began to wave and increased graduall y.When the ratio reached at maximum, the fault sliding instability, sliding velocity mutations and fault rock burst occurred. The overlying strata destruction caused by mi ning was the direct cause of fault rock burst and its root cause was changed of fault stress field.