The ratio of unconfined compressive strength to tensile strength (UCS/T) is a fundamental mechanical characteristics of rock materials, and the macroscopic mechanical properties of rocks under compression and tension conditions are seriously affected by microcracks. In this study, the numerical samples with three different microcrack distribution morphology (triangular mesh microcrack distribution morphology (T-MDM), Voronoi mesh microcrack distribution morphology (V-MDM), uniform microcrack distribution morphology (U-MDM)) were established based on different geometric forms. The effects of microcrack distribution morphology, microcrack density, and microcrack-matrix bond strength ratio on the mechanical properties of rocks were investigated, and the influence of various factors on the compression-tensile strength ratio was further discussed. Results showed that the rock samples with regular microcrack distribution morphology (T-MDM and V-MDM) exhibited a more reasonable compression-tensile strength ratio than those with random microcrack distribution morphology (U-MDM), and microcrack density has a significant effect on compression-tensile strength ratio under low bond strength ratio. Further, when the microcrack-matrix bond strength ratio is within the range of 0.05–0.15, the compression-tensile strength ratio of rock is basically between 10 and 30. The research results can provide reference for the construction of microstructure in numerical model and the simulation of reasonable mechanical behavior of rock.

无侧限抗压强度与抗拉强度之比（UCS / T）是岩石材料的基本力学特性，微裂纹严重影响岩石在压缩和拉伸条件下的宏观力学性能。在此研究中，基于以下三种不同的微裂纹分布形态（三角网状微裂纹分布形态（T-MDM），Voronoi网状微裂纹分布形态（V-MDM），均匀微裂纹分布形态（U-MDM））建立了数值样本。不同的几何形式。研究了微裂纹分布形态，微裂纹密度和微裂纹-基体结合强度比对岩石力学性能的影响，并进一步探讨了各种因素对抗压强度比的影响。结果表明，具有规则微裂纹分布形态的岩石样品（T-MDM和V-MDM）比具有随机微裂纹分布形态的岩石样品（U-MDM）表现出更合理的抗压强度比，并且微裂纹密度对随机裂纹具有显着影响。低粘结强度比下的压缩拉伸强度比。此外，当微裂纹-基体结合强度比在0.05-0.15范围内时，岩石的抗压强度比基本上在10到30之间。研究结果可为数值模型的建立和结构的建立提供参考。模拟合理的岩石力学行为。