【摘要】 为针对性解决Ⅳ级破碎岩体大跨度顶板的支护问题，基于封闭、组合拱和减跨作用原理，提出了“锚网+喷浆+预应力锚杆+预应力锚索”联合支护方式。采用Mohr-Coulomb准则，对围岩二次应力进行非关联弹塑性分析，结合分区边界条件，导出了可确定松动区与塑性强化区半径的解析式，得出松动区厚度2.53 m,塑性区厚度2.83 m,结合相关工程技术规范，对顶板支护参数进行了合理设计。为论证设计方案的可行性，利用FLAC 3D软件构建了9#采场物理模型，模拟分析了不支护、原支护方案与设计支护方案3种方案下顶板稳定性状态。结果表明：采用设计方案，顶板支护区域最小主应力降低至0～0.25 MPa,远低于顶板抗拉强度；塑性区高度降低至3.6 m,对比矿山原支护方案下降62.50%。根据设计方案与数值模拟结果，指导完成了9#采场顶板支护工业试验，回采过程中，顶板未发生任何冒落，整体性与稳定性较好，充分证明了设计方案的合理性和可行性，研究成果可为类似矿山提供一定的参考。更多还原

【Abstract】 To specifically address the support challenges posed by large-span roofs in Class IV fractured rock masses, a composite support scheme was proposed based on the principles of structural closure, arching effect, and span reduction. The scheme integrates a combination of anchor mesh, shotcrete, prestressed rock bolts, and prestressed anchor cables to achieve comprehensive reinforcement. A non-associated elasto-plastic analysis of the secondary stress field in the surrounding rock was performed based on the Mohr-Coulomb failure criterion. Considering the partitioned boundary conditions, analytical expressions were derived to determine the radii of the loosened zone and the plastic reinforcement zone. The calculated thicknesses of the loosened and plastic zones were 2.53 m and 2.83 m, respectively. Based on these results and relevant engineering standards, the support parameters for the roof were rationally designed. To verify the feasibility of the proposed scheme, a numerical model of Stope #9 was developed using FLAC3D software to simulate three scenarios: no support, the original support design, and the proposed support scheme. Simulation results indicated that the minimum principal stress in the supported roof area under the proposed scheme was reduced to 0～0.25 MPa, which is significantly lower than the tensile strength of the rock. The height of the plastic zone was reduced to 3.6 m, representing a 62.5% decrease compared to the original support design. An industrial-scale trial was subsequently carried out in Stope #9 based on the proposed design and simulation outcomes. During the excavation process, no roof collapse was observed, and the roof exhibited good integrity and stability. These results confirm the rationality and practical feasibility of the proposed support system and provide a valuable reference for similar underground mining projects.更多还原