Creep is a fundamental process responsible for the long-term crustal evolution and the stability of rock engineering. However, the influence of initial microcracks on the creep of rock has not been determined. Here, the influence of initial microcracks generated by repetitive impacts on the creep of sandstone is quantitatively investigated. Results show that the increase in the initial microcracks density reduces not only the compressive strength but also the stress of the crack damage threshold. Under the same creep stress, i.e. 24.6 MPa, the axial strain rate increases from 1.8×10⁻⁹ s⁻¹ to 3×10⁻⁶ s⁻¹ with the initial microcracks density increasing from 0.07 to 0.8. Both the axial strain and the cumulative acoustic emission (AE) energy at the onset of the tertiary creep phase increase with increasing initial microcracks density. The creep strain rate exhibits a quasi-linear relationship with the difference between the creep stress and the stress of the crack damage threshold. Based on the experimental results, a creep model considering the initial microcracks density is proposed. These results are helpful to better understand the long-term evolution of crust and stability of rock engineering with initial microcracks.

蠕变是影响地壳长期演化和岩石工程稳定性的基本过程。然而，初始微裂纹对岩石蠕变的影响尚未确定。在这里，定量研究了重复冲击产生的初始微裂纹对砂岩蠕变的影响。结果表明，初始微裂纹密度的增加不仅降低了抗压强度，还降低了裂纹损伤阈值的应力。在相同的蠕变应力，即24.6 MPa下，轴向应变率从1.8×10 ^-9 s ^-1增加到3×10 ^-6 s ^-1初始微裂纹密度从 0.07 增加到 0.8。第三蠕变阶段开始时的轴向应变和累积声发射 (AE) 能量都随着初始微裂纹密度的增加而增加。蠕变应变率与蠕变应力和裂纹损伤阈值应力的差值呈拟线性关系。基于实验结果，提出了考虑初始微裂纹密度的蠕变模型。这些结果有助于更好地理解具有初始微裂纹的地壳长期演化和岩石工程的稳定性。