非均称变形巷道变形破坏规律及支护对策

Support countermeasure and deformation law of roadway with non-symmetrical deformation

针对回采等造成的非均称变形巷道支护难题,采用实验室实验、数值模拟、理论分析和现场工业试验的综合方法,研究了非均称变形巷道围岩位移、应力和塑性区等围岩稳定性指标变化规律,以及高强度分区锚网索支护作用,提出了非均称变形巷道高强度分区锚网索支护技术。研究结果表明:煤层回采等造成巷道周围应力非均称分布,导致围岩变形以顶板非均称下沉和两帮不对称位移为主;靠近采空区侧煤帮强度弱化,促使巷帮及顶板深部岩体向塑性破坏状态转变,围岩稳定性急剧劣化;同时,巷道帮部稳定性与顶板稳定性呈非线性正比关系,随着帮部变形量增加,顶板下沉量急剧增加,而顶板急剧下沉加速帮部煤体破坏。对顶板和两帮分区设计支护参数,增大采空区侧煤帮承载能力,减小顶板及实体煤帮围岩破坏范围,提高顶板以及作为顶板基础的两帮强度和抗变形能力,有效控制巷道非均称变形。

Aiming at supporting difficulties of non-symmetrical deformation roadway caused by backstopping, lab experiment,numerical stimulation, theoretical analysis and industrial field test have been adopted to study the change rule of roadway＇s stability indexes of the displacement, stress and plastic zone of non-symmetrical deformation roadway, and to determine the supporting function of highstrength partition anchor cable, based on which,the supporting technique of high-strength partition anchor cable of non-symmetrical stability roadway has been introduced. The results have shown that the non-symmetrical distribution of stress around roadway caused by coal seam recovery has led to that the non-symmetrical sinking of roof and non-symmetrical displacement of sides are main characteristics of roadway deformation. The strength of coal sidewall deformation has weakened, which has caused the roadside and the rock in deep roof to transform to plastic failure and has badly deteriorated the stability of the surrounding rock. Meanwhile, the stability of roadway sides and that of roof is of nonlinear proportional relationship, which means that as the deformation of roadway sides increases,the sinking will rapidly increase and accelerate the failure of sidewall coal. Partition supporting parameters would be designed on roof and sides for increasing loading capacity of gob coal side, decreasing the effect of the failure area of roof and coal side, enhancing the strength and anti-deformation ability of roof and sides as the base of roof rock and effectively controls the non-symmetrical deformation of roadway.