坚硬顶板切顶成巷挡矸结构变形与破坏机理研究

    Deformation and failure mechanism of retaining gangue structure in hard roof cutting and roadway formation

    • 摘要: 针对坚硬顶板切顶成巷过程中挡矸结构易弯曲、偏移问题,以邱集煤矿11煤1105工作面运输巷为研究对象,构建全过程挡矸结构力学模型,并结合ABAQUS数值模拟软件分别模拟了受矸石冲击、挤压时挡矸结构受力变形情况。研究结果表明:坚硬顶板垮落矸石冲压特征明显,易导致挡矸结构横向弯曲,尤其是挡矸结构中工字钢上部变形严重,通过对工字钢顶端施加横向约束力,可有效减小工字钢变形;受矸石挤压作用,金属网发生网兜变形,并对相邻工字钢产生较大的拉应力,易造成整体失稳;工字钢间距800 mm时钢筋网变形量降低明显。提出1种新型挡矸支护方案,经现场实施监测,新方案下矸石帮变形减小了约49%,满足生产安全需要。

       

      Abstract: For the problem of retaining gangue bending and skewing in the process of hard roof cutting roadway, this paper takes the 11# coal 1105 working face haulage roadway of Qiuji Coal Mine as the object of study and builds the mechanical model of gangue retaining in the whole process. Then the stress and deformation of the retaining gangue structure under the impact and extrusion of gangue are simulated with the numerical calculation software ABAQUS, respectively. The results show that the hard roof caving gangue has obvious punching characteristics, which can easily lead to the lateral bending of the retaining gangue, especially the upper part of the I-steel in retaining gangue, and can effectively reduce the deformation of the I-steel by imposing a lateral constraint on the top of the I-steel. The metal mesh will deform and produce large tensile stress on the adjacent I-steel under the extrusion of gangue, which is easy to cause overall instability. The deformation of the steel mesh will be significantly reduced when the spacing between I-steels is 800 mm. A new gangue retaining support scheme is proposed. According to field monitoring, the deformation of the waste rock slope under the new scheme has been reduced by about 49 %, which is in line with production safety requirements.

       

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