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巷道掘进主动分区与顶板稳定耦合的时空响应特性

Spatiotemporal response characteristics of the coupling between active zoning in roadway excavation and roof stability

  • 摘要: 掘锚一体化快速掘进是破解煤矿采掘失衡、释放先进产能及践行智能少人掘进的关键路径。文章基于掘锚一体机组,针对其主动分区快速掘进的锚护机制及带来的顶板稳定问题开展研究,阐明了设备在巷道轴向-横向断面协同锚护特征、量化了设备参数与掘进速度关系、明确掘锚并行分区锚护机制,建立迎头顶板分区Reissner厚板力学模型、引入全新势函数求解空间尺度和挠度同三向应力关系式,并结合数值模拟分析部分锚护区变化对迎头顶板稳定的时空特性,揭示快速掘进主动分区支护后空顶区顶板失稳机理,最后巷道表面位移、钻孔窥视、锚杆(索)受力等实测验证了研究合理性。研究表明:合理量化掘锚一体机与锚杆转载机的特征参数与巷道掘进速度的动态耦合关系实现“设备参数→支护空间分区→时空参量”时空转化和分区参数确定;Reissner厚板模型表明部分锚护区支护强度存在顶板下沉量与应力集中现象显著缓解的临界值,部分锚护区长度存在允许的最佳临界区间;巷道特定条件数值模拟显示,部分锚护区长度从4 m增加至10 m,顶板垂直位移、垂直应力呈现显著增大、显著降低特征,滞后支护时间由及时支护延长时,顶板位移持续增长且应力释放加剧、塑性区范围显著扩大,围岩自承能力明显弱化;矿压实测主动分区巷道的表面位移、锚杆受力均“先极速提升−后缓慢增加−终趋于稳定”,钻孔裂隙经历从空顶区扩展至部分锚护压密减少直至全部锚护后闭合的动态演化过程,说明巷道顶板在经历主动分区锚护至全部锚护后,深部裂隙、表面位移、锚杆锚索受力均趋于稳定,实现了主动分区并行工艺与顶板稳定的耦合,为分区锚护快速掘进应用提供理论依据。

     

    Abstract: Integrated tunneling and bolting for rapid excavation represents a key pathway to resolving the imbalance between mining and excavation, unleashing advanced production capacity, and implementing intelligent, minimally-manned tunneling operations.Based on the bolter miner system, this study investigates its active zoning rapid excavation support mechanism and the resulting roof stability issues. It clarifies the equipment's coordinated support characteristics in both the axial direction and cross-sectional profile of the roadway, quantifies the relationship between equipment parameters and excavation speed, and defines the parallel tunneling-bolting zoning support mechanism. A Reissner thick-plate mechanical model is established for the zonal heading roof, and a new potential function is introduced to derive the relationship among spatial dimensions, deflection, and three-dimensional stress. Combined with numerical simulation, the spatiotemporal effects of variations in the partially supported zone on heading roof stability are analyzed, revealing the instability mechanism of the unsupported roof area following active zoning support during rapid excavation. Finally, field measurements, including roadway surface displacement, borehole imaging, and bolt (cable) stress, validate the rationality of the research.The study demonstrates that rationally quantifying the dynamic coupling relationship between the characteristic parameters of the integrated tunneling-bolting unit and the roadway advance rate enables the spatiotemporal transformation from “equipment parameters → support zone partitioning → spatiotemporal parameters” and facilitates the determination of zoning parameters. The Reissner thick-plate model indicates the existence of a critical value for the support intensity in the partially supported zone, beyond which roof subsidence and stress concentration are significantly alleviated, and identifies an optimal critical range for the length of the partially supported zone. Numerical simulations under specific roadway conditions reveal that as the length of the partially supported zone increases from 4 m to 10 m, the vertical displacement of the roof increases significantly while the vertical stress decreases markedly. When the lagging support time is extended from immediate to delayed support, roof displacement continues to grow, stress release intensifies, the plastic zone expands notably, and the self-supporting capacity of the surrounding rock weakens considerably. Field measurements in actively zoned roadways show that both surface displacement and bolt stress exhibit a trend of “initial rapid increase, followed by gradual growth, and eventual stabilization.” Borehole fractures undergo a dynamic evolution process: initially propagating from the unsupported zone, then being compacted and reduced in the partially supported zone, and finally closing after full support is installed. This indicates that after progressing from active zonal support to complete support, deep fractures, surface displacement, and bolt/cable stresses in the roadway roof all tend to stabilize. Thus, the coupling between the active parallel zoning process and roof stability is achieved, providing a theoretical foundation for the application of zoned support in rapid excavation.

     

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