重复采动软岩巷道非对称变形机理与控制技术

Asymmetric deformation mechanism of soft rock roadway under repeated mining and the control technology

为研究厚煤层综放面软岩巷道受重复采动影响下非对称变形机理,以布尔台煤矿42203综放工作面为工程背景,采用了现场监测、理论分析及数值模拟等方法对42203辅运巷道受重复采动影响时巷道非对称变形破坏特征及破坏机理进行研究,提出了重复采动软岩巷道高强锚索补强支护技术。研究结果表明:42203辅运巷道受重复采动影响导致两帮变形大于顶底变形,正帮上部及副帮下部帮鼓破碎,矿压显现剧烈,采动超前影响范围可达110 m,重复采动产生的高偏应力,改变了侧压系数及应力方向,致使塑性区由近似对称破坏转变为非对称破坏,揭示了重复采动巷道破坏机理,提出了采用高强锚索对42203辅运巷道进行补强支护方案,经现场实测,该方案有效减缓了围岩的变形速度和变形总量,满足巷道稳定要求,效果良好。

In order to study the asymmetric deformation mechanism of the soft rock roadway under the influence of repeated mining in the fully mechanized top-coal caving face of thick coal seam,taking the 42203 working face of Buertai Coal Mine as the engineering background,the field monitoring,theoretical analysis and numerical simulation methods were used to study the asymmetric deformation and failure characteristics and failure mechanism of the 42203 auxiliary haulage roadway under repeated mining,and the high-strength anchor cable reinforcement support technology for the soft rock roadway under repeated mining was proposed.The research results show that the deformation of the roadway two sides is greater than the deformation of the roof and floor due to repeated mining,the upper side of the front side and the lower side of the auxiliary side are broken,the mine pressure behavior is violent,the mining advance influence range is up to 110 m,the high deviatoric stress caused by repeated mining changes the lateral pressure coefficient and stress direction,causing the plastic zone to change from approximately symmetric damage to asymmetric damage,revealing the damage mechanism of the repeated mining roadway.The roadway reinforcement and support scheme using high-strength anchor cable was proposed.According to the field measurement,this scheme slowed down the deformation and reduced the total deformation of surrounding rock,meeting the requirements of roadway stability,and favorable effect was achieved.