Abstract Coal burst induced by fault-slip in longwall mining can adversely influence underground mining activities. This paper analyses the source mechanisms of fault-slip behaviour using a numerical fast Lagrangian analysis of continua in three dimensions (FLAC3D) model. The fault was simulated by the build in zero-thickness interface elements. The post failure process of fault-slip was studied using the linear slip weakening law which was implemented in a user-defined FISH program. The numerical results showed that the fault-slip presented significantly different trends at different positions along the fault. Seismic events mainly occurred at the fault area where the normal stresses reduced drastically. Few seismic events occurred when the distance between the longwall face and the fault was less than 20 m. For the parameters of the linear slip weakening law, the influence of the dynamic friction and the critical slip distance were analysed. These two parameters have significant impact on the occurrence of seismic events and the source parameters of fault-slip. The parametric study showed that fault-slip with around 0.1 m of critical slip distance was able to release larger seismic energy than fault-slip with both less and greater than 0.1 m of critical slip distance. The outcomes of this paper help to better understand the seismic fault-slip process in longwall mining and the influence of the critical parameters of the linear slip weakening law on seismic fault-slip behaviour.

中文翻译：

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基于线性滑移弱化规律的长壁开采断层滑移行为数值分析

摘要 长壁开采中断层滑移引起的煤爆会对地下开采活动产生不利影响。本文使用三维连续体的数值快速拉格朗日分析 (FLAC3D) 模型分析断层滑动行为的源机制。故障是通过内置零厚度界面元素来模拟的。使用在用户定义的 FISH 程序中实现的线性滑动弱化定律研究断层滑动的失效后过程。数值结果表明，断层滑动在沿断层不同位置呈现出明显不同的趋势。地震事件主要发生在正应力急剧下降的断层区。当长壁工作面与断层的距离小于 20 m 时，很少发生地震事件。对于线性滑移弱化定律的参数，分析了动摩擦和临界滑移距离的影响。这两个参数对地震事件的发生和断层滑动的震源参数有重要影响。参数研究表明，与临界滑动距离小于和大于0.1 m的断层滑动相比，具有约0.1 m临界滑动距离的断层滑动能够释放更大的地震能量。本文的研究结果有助于更好地理解长壁开采中的地震断层滑动过程以及线性滑动减弱定律的关键参数对地震断层滑动行为的影响。这两个参数对地震事件的发生和断层滑动的震源参数有重要影响。参数研究表明，与临界滑动距离小于和大于0.1 m的断层滑动相比，具有约0.1 m临界滑动距离的断层滑动能够释放更大的地震能量。本文的研究结果有助于更好地理解长壁开采中的地震断层滑动过程以及线性滑动减弱定律的关键参数对地震断层滑动行为的影响。这两个参数对地震事件的发生和断层滑动的震源参数有重要影响。参数研究表明，与临界滑动距离小于和大于0.1 m的断层滑动相比，具有约0.1 m临界滑动距离的断层滑动能够释放更大的地震能量。本文的研究结果有助于更好地理解长壁开采中的地震断层滑动过程以及线性滑动减弱定律的关键参数对地震断层滑动行为的影响。