为探究煤起裂强度关键影响因素及其对各因素响应敏感度，采用裂纹体积应变法和声发射 法确定煤样单轴载荷下起裂强度。 基于煤样 CT 扫描结果，二值化得到内部结构缺陷分布状态，并 进行修正建立 DFN 网格模型，采用合成岩体方法( SRM) 重构数值岩芯，无侧限加载再现煤样破坏 过程，得到数值岩芯峰值强度、起裂强度、起裂模式及起裂位置。 将起裂强度影响因素分为煤样基 质骨架、基质间相互作用及原生缺陷 3 类，从中各选取 2 项指标，采用响应面法进行单因素及交互 分析。 采用裂纹应变法及声发射法确定煤起裂强度为 10.06 及 9.26 MPa，分别为峰值强度的50.3% 和 46.7%;数值岩芯起裂强度为 9.56 MPa，为峰值强度的 47.2%，且均在原生缺陷尖端发生拉破坏 而起裂。 单因素分析结果显示，煤起裂强度对各因素响应敏感性依次为 DFN 网格密度>基质颗粒 弹性模量 = PBM 模型黏聚力>SJ 模型摩擦因数>PBM 模型抗拉强度>基质孔隙率，表明原生缺陷对 起裂强度影响最显著。 多因素交互影响分析发现，颗粒弹性模量与 PBM 模型黏聚力交互作用响应 曲线扭曲程度最高，表明 2 者对煤样起裂强度影响的交互作用最明显;微观力学因素与 DFN 网格 密度交互作用响应曲面较陡，且投影等值线在 DFN 网格密度方向更密集，证明煤样内部结构特征 对其宏观力学性质影响更显著，与单因素分析结果相互佐证。 现场实测表明，巷帮浅部煤体破碎程 度高，强度较低，注浆充填结构缺陷后，煤体完整性、均质性及强度得到提高。

In order to explore the key influencing factors of coal cracking strength and its response sensitivity to various factors，the crack volume strain method and acoustic emission method were used to determine the crack initiation strength of coal samples under uniaxial load. Based on the CT scanning results of coal samples，the distribution state of internal structural defects was obtained by binarization，and the DFN grid model was established. The numerical core was reconstructed by the synthetic rock mass method(SRM)，the failure process of coal sample was reproduced by un⁃ confined loading，and the fracture initiation strength，mode and location of numerical core were obtained. The influen⁃ cing factors of cracking strength were divided into three categories:matrix framework，matrix interaction and prima⁃ ry defects. Two indexes were selected from each of them，and single factor and interactive analysis were conducted by response surface method. The results show that the crack initiation strength of coal is 10.06 MPa and 9.26 MPa re⁃ spectively by crack strain method and acoustic emission method，and the numerical core crack initiation strength is 9.56 MPa，which is 47.2% of the peak strength. The results of single factor analysis show that the sensitivity of coal cracking strength to each factor is DFN grid density > matrix particle elastic modulus = PBM model cohesion > SJ model friction coefficient > matrix porosity，indicating that the primary defects have the most significant effect on the fracture initiation strength. The results of multi - factor interaction analysis show that the interaction re⁃ sponse curve of particle elastic modulus and PBM model cohesion has the highest distortion degree， which indicates that the interaction between them on coal sample cracking strength is more obvious. The interaction response surface between micromechanical factors and DFN grid density is steeper，and the projection isoline is more dense in the direction of DFN grid density，which proves that the internal structure characteristics of coal sample have great influence on coal sample cracking strength. The effect of mechanical properties is more significant，which is consistent with the results of single factor analysis. The field measurement shows that the coal body in the shallow part of the roadway has a high degree of fragmentation and low strength. After grouting and filling structural defects， the integrity，homogeneity and strength of coal body are improved.