巷道围岩偏应力分布规律及破坏机理探究

Study on deviatoric stress distribution law and failure mechanism of roadway surrounding rock

回采巷道围岩塑性区形态分布特征是巷道稳定控制的关键问题。以锦界煤矿31117工作面为工程背景,基于最大主偏应力以及巷道蝶形破坏理论,揭示了31117巷道出现大变形破坏的原因。研究结果表明,在不同应力场下,最大主偏应力存在圆形、椭圆形、X形3种破坏形态。同时,巷道围岩塑性区形态与最大主偏应力形态具有对应关系,以最大主偏应力为指标,可以在一定程度上揭示巷道围岩变形破坏机理。31117巷道在高偏应力作用下,导致巷道顶板两侧出现挤压破坏,基于偏应力分布形态,提出巷道关键控制技术。

The distribution characteristics of plastic zone morphology in surrounding rock of mining roadway are the key issue of roadway stability control.Taking 31117 working face of Jinjie Coal Mine as the engineering background,based on the maximum principal deviatoric stress and the butterfly failure theory of roadway,the causes of large deformation and failure in 31117 roadway were revealed.The results showed that under different stress fields,the maximum principal deviatoric stress had three failure modes:circular,elliptical and X-shaped.At the same time,the plastic zone morphology of roadway surrounding rock had a corresponding relationship with the maximum principal deviatoric stress morphology,thereby taking the maximum principal deviatoric stress as an index,the deformation and failure mechanism of roadway surrounding rock could be revealed to a certain extent.Under the action of high deviatoric stress,squeezing damage occurred on both sides of the 31117 roadway roof.Based on the distribution of deviatoric stress,the key control technologies of roadway were put forward.