高水平应力下大断面巷道围岩破坏机理及支护方案

Failure Mechanism and Support Scheme of Large Section Roadway Surrounding Rock Under High Horizontal Stress

为研究水平构造应力下大断面巷道围岩破坏机理,基于压力拱理论分析了巷道跨度对巷道围岩稳定的影响,并在理论上分析了水平构造应力对巷道顶板和两帮的影响,通过建立PHASE2D数值模型,分别模拟了不同巷道断面和水平应力下的巷道围岩应力和位移分布,表明巷道跨度的增大对巷道顶板两侧有较大影响,使其水平和垂直应力集中系数增大,强度系数减小,巷道顶板两侧围岩更易失稳破坏。随着侧压系数增大,巷道两帮强度系数大范围减小,表明水平应力的增大会使两帮煤体发生破坏。最后通过具体案列对理论分析结果进行了验证,提出了合理的支护方案。

In order to study the failure mechanism of roadway surrounding rock under horizontal structural stress, we analyzed the influence of roadway span on the stability of roadway surrounding rock based on the pressure arch theory, theoretically analyzed the horizontal tectonic stress influence on roadway roof and two sides, and simulated the different roadway cross sections and horizontal stress of the roadway surrounding rock stress and displacement distribution through the establishment of PHASE2 D numerical model, it shows that the increase of roadway span has a great influence on both sides of roadway roof, which makes the horizontal and vertical stress concentration coefficients increase, the strength coefficient decrease, and the surrounding rocks on both sides of roadway roof are more vulnerable to instability and failure. With the increase of side pressure coefficient, the strength coefficient of two sides of roadway decreases in a large range, it indicates that the increase of horizontal stress will cause the failure of two sides of coal body. At last, we verified the theoretical analysis results by the specific case list, and proposed a reasonable support scheme.