【摘要】 针对多次扩孔施工引发的钻孔围岩多重损伤问题，通过理论分析与COMSOL数值模拟，分析了不同直径钻孔煤体应力分布和损伤演化规律。基于Mohr-Coulomb强度准则和弹塑性力学方程，推导破碎区与塑性区半径的理论解。结合寺家庄煤矿15115工作面地质参数，构建单次成孔与多级扩孔条件下钻孔开挖模型。研究表明：单次成孔直径由113 mm增至400 mm，塑性区面积扩大6.6倍，径向应力峰值点外移。多级扩孔施工中，前期钻孔扰动导致后续扩孔应力集中区显著扩展，终孔直径400 mm时，应力集中区范围增大7.31%，塑性区面积扩大10.8倍，应力峰值由11.68 MPa升至11.91 MPa。研究成果为钻孔设计提供理论依据。更多还原

【Abstract】 In response to the problem of multiple damage to the surrounding rock of boreholes caused by multi-stage reaming operations, this study analyzed the stress distribution and damage evolution law of coal mass around boreholes of different diameters through theoretical analysis and COMSOL numerical simulation. Based on the Mohr-Coulomb strength criterion and elastoplastic mechanics equations, theoretical solutions for the radii of the fractured zone and plastic zone were derived. A borehole excavation model under conditions of single drilling and multi-stage reaming was constructed,incorporating the geological parameters of the 15115 working face in Sijiazhuang Coal Mine. The research indicates that: When the diameter of a single borehole increases from 113 mm to 400 mm, the area of the plastic zone expands by 6.6 times, and the point of peak radial stress shifts outward, In multi-stage reaming operations, the disturbance from earlier drilling stages leads to a significant expansion of the stress concentration zone during subsequent reaming. When the final borehole diameter reaches400 mm, the range of the stress concentration zone increases by 7.31%, the area of the plastic zone increases by 10.8 times, and the peak stress rises from 11.68 MPa to 11.91 MPa, compared to singlestage drilling. The research results provide a theoretical basis for borehole design.更多还原