浅埋深切顶卸压自成巷淋水段顶板支护参数研究

Research on roof support parameters of shallow-buried deep roof cutting and pressure relief self-formed roadway watering section

某煤矿某工作面切顶卸压巷道淋水段顶板变形量较大,不利于切顶卸压自成巷技术推进,为避免留巷及后期复用过程中出现安全隐患,保障留巷完整性,通过在切顶卸压巷道实体煤侧顶板补充支护恒阻锚索,达到控制巷道顶板变形的目的,利用FLAC^(3D)数值模拟软件建立数值计算模型,对补充支护前后的巷道顶板垂直位移分布及巷道围岩垂直与水平应力分布图进行研究。研究结果表明,各种支护手段下的巷道顶板都呈现出明显的倾斜变形特点,在采用优化支护设计方案1后,切缝侧顶板变形量减少8.04%,巷道中部顶板变形量减少10.86%,实体煤侧顶板变形量减少16.13%,实体煤侧顶板与切缝侧顶板的变形量差值则增加60.78%,不仅有效减少了顶板总体变形量,也增加了实体煤侧顶板与切缝侧顶板的变形量差值,有利于下一采面回采的巷道复用;通过在实体煤帮侧顶板补充支护恒阻锚索,能够有效减小巷道切缝侧顶板垂直应力,缩小水平应力集中范围;减小恒阻锚索排距无明显控制效果,方案2与方案1相比对顶板变形量、垂直应力和水平应力分布的影响并不显著;现场留巷效果良好,证明通过在实体煤帮侧进行恒阻锚索补充支护能够有效地控制切顶卸压自成巷顶板变形,保障所留巷道完整与留巷复用安全。

The roof deformation in the watering section of the roof cutting and pressure relief roadway of a certain working face of a certain coal mine is large,which is not conducive to the promotion of the technology of self-forming roadway for roof cutting and pressure relief.In order to avoid safety risks in the process of retaining roadway and later reuse,and to ensure the integrity of retaining roadway,the roof deformation of roadway is controlled by adding constant resistance anchor cable to the solid coal side roof of the roof cutting and pressure relief roadway.Using FLAC^(3D)numerical simulation software,a numerical calculation model was established to study the vertical displacement distribution of roadway roof and the vertical and horizontal stress distribution of roadway surrounding rock before and after the supplementary support.The research results showed that the roof of the roadway under various support methods presented obvious characteristics of inclined deformation.After adopting the optimized support design schemeⅠ,the roof deformation on the cutting seam side was reduced by 8.04%,the roof deformation in the middle of the roadway was reduced by 10.86%,the roof deformation on the solid coal side was reduced by 16.13%,and the deformation difference between the solid coal side roof and the roof on the cutting seam side was increased by 60.78%.It not only effectively reduced the total deformation of the roof,but also increased the deformation difference between the solid coal side roof and the cutting seam side roof,which was conducive to the roadway reuse of the next mining face.By supplementing the support with constant resistance anchor cables to the solid coal side roof,the vertical stress on the cutting seam side roof of the roadway can be effectively reduced,and the range of horizontal stress concentration can be narrowed;reducing the spacing of constant resistance anchor cables has no significant control effect,and comparing with schemeⅠ,schemeⅡhad no significant impact on roof deformation,vertical stress,and horizontal stress distribution;the on-site effect of retaining the roadway was good,which proved that by supplementing the support with constant resistance anchor cables on the solid coal side,the deformation of the self-formed roadway roof can be effectively controlled through roof cutting and pressure relief,ensuring the integrity of the retained roadway and the safety of its reuse.