断层影响下底板应力分布和破坏分析

采用FLAC5.02D数值模拟软件模拟了煤层开采过程中断层对底板应力峰值与塑性区变化的影响。对不同断层倾角，断层刚度和底板水压下底板应力峰值和塑性区变化进行了分析，同时根据现场实测，对有无断层条件下破坏深度进行对比。断层倾角越小，底板应力峰值越高，底板破坏区范围越大；断层倾角越大，底板破坏区范围越小，最终发展为“X”型。断层刚度的增加，没有对底板塑性区产生明显的影响，只是从断层带一侧改善了底板突水通道。随着底板水压的增大，塑性区范围没有明显变化，底板应力峰值的波动程度也不大。无断层存在，底板破坏深度为0~17 m；断层带的存在使底板破坏深度增大了135%。

Analysis of the Stress Distribution and the Failure of the Floor under the Influence of Fault

The impact of the fault on the stress peak and the variation of plastic zone during coal bed mining was simulated by using FLAC5.02D numerical simulation software.Different fault dip，fault stiffness and the variations of the stress peak and the plastic zone under floor water pressure were analyzed.Meanwhile，according to the field measurement，the damage depth with or without fault is compared.The smaller the fault dip is，the higher the floor stress peak value and the larger the floor failure zone is.The larger the fault dip is，the smaller the damage zone is，eventually developing as “X”type.With the increase of the fault stiffness，it has no obvious influence on the floor plastic zone，but only improves water inrush channel from one side of the fault.With the increase of the floor water pressure，the plastic zone did not change significantly，and the volatility of the floor peak stress is not large.No fault exists，the floor failure depth is 0~17 m.The fault zone makes the floor failure depth increasing by 135%.