高级检索

高应力破碎巷道失稳演化机制与协同控制技术

Instability evolution mechanism and collaborative control technology of high-stress fractured roadways

  • 摘要: 针对厚煤层下分层开采中高应力破碎顶板巷道支护难题,以赵固二矿14022工作面回风巷为工程背景,建立了高应力状态下破碎围岩破坏特征的顶板力学模型,获得了弹性状态下的底板应力分布特征,明确了底板应力分布的旋转特征,推导了三维应力环境下的围岩塑性区方程,获得了巷道围岩的塑性分布特征。结果表明:受上部煤层采动扰动影响,围岩应力分布呈现显著的方向性偏转,主应力方向发生明显改变。主应力方向偏转导致围岩塑性区呈现显著的非对称分布特征,塑性区集中发育于巷道顶板及左帮区域,引发围岩非对称破坏。主应力方向偏转与上覆岩层破碎的叠加作用是导致巷道围岩发生严重非对称破坏的根本原因。此外,受采动影响,上覆岩层底板破碎,进一步加剧了巷道顶板的破坏程度,造成锚索锚固失效与钢棚支护效果显著下降。基于此,研发了新型双液注浆材料,提出了“注浆加固+锚索非对称”联合支护方案。现场应用表明,巷道顶底板变形量降低36%,两帮变形量降低51%,显著抑制了围岩变形,提高了顶板岩层稳定性,为类似条件巷道支护提供了可靠的技术参考。

     

    Abstract: Addressing the support challenges of roadways with high-stress broken roofs during mining in the lower slice of thick coal seams. Taking the upper entry of the 14022 working face in Zhaogu No. 2 Mine as the engineering background, a roof mechanical model for the failure characteristics of broken surrounding rock under high-stress conditions was established. The stress distribution characteristics of the floor in an elastic state were obtained, and the rotational characteristics of floor stress distribution were clarified. The plastic zone equation of surrounding rock under a three-dimensional stress environment was derived, and the plastic distribution characteristics of roadway surrounding rock were obtained. The research results show that: under the disturbance of mining in the upper coal seam, the stress distribution of the surrounding rock exhibits significant directional deflection, with the principal stress direction changing markedly. This principal stress deflection leads to an obvious asymmetric distribution of the plastic zone in the surrounding rock, with the plastic zone concentrated in the roof and left rib of the roadway, inducing asymmetric failure of the surrounding rock. The combined effect of principal stress deflection and the fragmentation of the overlying strata is the fundamental cause of severe asymmetric failure of the roadway surrounding rock. Furthermore, due to mining disturbances, the floor of the overlying strata becomes broken, further exacerbating the failure degree of the roadway roof, resulting in anchor cable anchorage failure and a significant decrease in the support effect of steel sheds. Based on this, a new type of two-component grouting material was developed, and a combined support scheme of “grouting reinforcement + asymmetric anchor cables” was proposed. Field application shows that the deformation of the roadway roof and floor decreased by 36%, and the deformation of the two ribs decreased by 51%, significantly restraining surrounding rock deformation and improving roof stability, providing a reliable technical reference for roadway support under similar conditions.

     

/

返回文章
返回