为分析沿空双巷围岩失稳破坏特征,采用大型物理模拟试验系统,结合数字照相分析技术,分别研究了沿空双巷无支护情况下围岩破坏演化全过程、围岩变形规律以及巷道围岩破裂形式。试验结果表明:在沿空双巷布置系统中,巷间煤柱成为围岩承载结构中的关键及薄弱部位,其压缩失稳是造成双巷顶板产生较大下沉位移的直接原因,而顶板的冒落破坏进而诱使巷道帮部围岩产生大面积的剪切破坏。沿空双巷围岩的失稳平衡过程主要分为初期弹塑性变形阶段、稳定过渡阶段、失稳破坏阶段、二次稳定阶段4个阶段。
In order to analyze the instability and failure of the double gob-side entry,the deformation-failure evolution,the deformation law of the surrounding rock and the rock rupture modes are studied by using the methods of physical model and digital photogrammetry.The results show that in the roadway-arrangement system of the double gob-side entry,the middle pillar is the key and weak site in the rock bearing structure,and its instability causes the sinking displacement of the roof.Furthermore,the roof falling induces the shear failure area on the sidewall.The process of surrounding rock instability can be divided into four stages: elastic-plastic deformation,stable transition,unstable failure,and quadratic stability.