重复采动巷道塑性区调控原理与稳定控制

为研究双巷布置工作面留巷受重复采动影响围岩的变形破坏规律及稳定控制问题，综合运用数值模拟、理论分析和现场观测等方法，研究双巷间距对重复采动下留巷围岩塑性区空间分布特征及偏应力的影响规律，揭示二次采动对留巷塑性区的诱导扩展机制，提出围岩塑性区二次扩展抑制方法。结果表明：重复采动巷道围岩塑性区在巷道轴向上均可划分为6个区域，整体表现为双巷间距越大，则塑性区破坏深度越小的特征，且其形态由非对称分布向对称分布状态转化，双巷距离增加造成的应力旋转程度和偏应力峰值低是主要原因。一次采动滞后影响稳定区维护距离及周期最长，且为二次采动塑性区叠加扩展的基础，是重复采动巷道围岩稳定的关键控制区域。据此提出通过调整巷道空间位置，达到改善应力环境、调整巷道围岩破坏状态的目的，并建立了分区补强支护相结合的调控方法和控制技术体系。现场实测结果表明，该技术体系能够达到巷道安全稳定目的，效果良好。

Regulation principle and stability control of plastic zone in repeated mining roadway

In order to study the deformation and failure laws and stability control of surrounding rock under the influence of repeated mining in double roadway layout working face, numerical simulation, theoretical analysis and field observation were conducted to analyze the influence of double roadway spacing on the spatial distribution characteristics and deviatoric stress of plastic zone under repeated mining. The induced expansion mechanism of secondary mining on plastic zone of retaining roadway was revealed, and the second expansion inhibition method of rock plastic zone was proposed. The results show that the plastic zone of surrounding rock in repeated mining roadway can be divided into six areas in the axial direction of roadway, the larger the distance between two roadways is, the smaller the damage depth of plastic zone is, and its shape changes from asymmetric distribution to symmetric distribution. The main reason is that the stress rotation degree and the peak value of deviator stress caused by the increase of distance between two roadways are low. One mining hysteresis affects the longest maintenance distances and cycles in the stability zone and it is the basis of superimposed expansion of plastic zone in secondary mining, and it is the key control area of surrounding rock stability in repeated mining roadway. On the basis of this, the purpose of improving the stress environment and adjusting the failure state of surrounding rock of roadway can be reached by adjusting the spatial position of roadway. Besides, the control method and control technology system of regional reinforcement and support were established. The field measurement results show that the technical system can achieve the goal of roadway safety and stability, and the effect is satisfactory.