To study the damage characteristics of rock mass under multi-level creep load, damage variable D was defined based on the spatio-temporal evolution characteristics of deformation modulus E, and the Kachanov damage theory is used to describe the damage evolution, then the damage evolution equation of the rock mass under multi-level creep load is obtained. Combining the damage evolution equation with the Lemaitre strain equivalence principle, the creep damage constitutive model of rock mass under multi-level creep load considering initial damage is obtained. By comparing the results of uniaxial and triaxial tests with the calculated values of the model, the rationality, reliability, application range of the model proposed in this paper is verified. According to the results of parameter inversion, obtain the relationship between damage, stress and time. Results show that time and stress are the important factors influencing the damage of rock mass under multi-level creep loading, the damage increases with time and stress level. However, the influence of time and stress on damage has a significant stress response characteristics: under low stress, the instantaneous damage D_is caused by the instantaneous stress loading is the main reason for the damage. With the increase of the load level, the main cause of the damage gradually changes from the instantaneous loading of the stress to the creep accumulation of the damage, and the greater the initial damage, the higher the time-dependent damage D_iT proportion in the global damage.

为了研究多级蠕变载荷作用下岩体的破坏特征，基于变形模量E的时空演化特征定义了破坏变量D。，用Kachanov损伤理论描述损伤演化，得到了多级蠕变载荷作用下岩体的损伤演化方程。结合损伤演化方程和Lemaitre应变当量原理，得到考虑初始损伤的多水平蠕变载荷作用下岩体的蠕变损伤本构模型。通过将单轴和三轴试验的结果与模型的计算值进行比较，验证了本文提出的模型的合理性，可靠性，适用范围。根据参数反演的结果，获得损伤，应力和时间之间的关系。结果表明，时间和应力是影响多水平蠕变荷载作用下岩体破坏的重要因素，破坏程度随时间和应力水平的增加而增大。D_是由瞬时应力加载引起的损坏的主要原因。随着载荷水平的增加，损伤的主要原因从应力的瞬时载荷到损伤的蠕变累积逐渐变化，并且初始损伤越大，则随时间变化的损伤D _iT比例就越高。全球破坏。