Cyclic stress variation induced by mining activities has a significant effect on the stability of surrounding rock and mining pillar in deep underground engineering. The influence of alternating cyclic loading and unloading tests on creep behavior of sandstone was investigated to explore the mechanism of the effect of the cyclic stress variation on the stability of rock. Firstly, a series of uniaxial constant strain rate and multi-step monotonic creep tests of sandstone were carried out to determine the maximum high loading stress and the minimum low loading stress in the alternating cyclic creep tests. Then the alternating cyclic loading and unloading creep tests were conducted to investigate the effects of loading paths and loading histories of cyclic high stress creep and low stress creep on the creep behavior of sandstone. Acoustic emission events, axial strain rate and lateral strain rate were also analyzed. The experimental results show that loading paths and loading histories of high stress creep and low stress creep have a significant influence on the alternating cyclic creep behavior of sandstone. The loading paths could accelerate the damage in the rock sample, which can be demonstrated by much larger plastic strain occurring in the damaged sample and larger viscous strain in the creep behavior of less damaged sample. The loading histories could increase viscous strain and plastic strain in the damaged sample. The maximum and the minimum loading stresses determined by the unstable crack threshold provide the basis of the unstable cracks growth in rock sample. The work presented in the present paper is helpful to understand the mechanical behaviors of rock mass under cyclic underground mining activities.

采矿活动引起的周期性应力变化对深部地下工程围岩和矿柱的稳定性有显着影响。研究交替循环加卸载试验对砂岩蠕变行为的影响，探讨循环应力变化对岩石稳定性影响的机理。首先，对砂岩进行了一系列单轴恒应变率和多步单调蠕变试验，确定了交替循环蠕变试验中的最大高加载应力和最小低加载应力。然后进行交替循环加载和卸载蠕变试验，研究循环高应力蠕变和低应力蠕变的加载路径和加载历史对砂岩蠕变行为的影响。还分析了声发射事件、轴向应变率和横向应变率。试验结果表明，高应力蠕变和低应力蠕变的加载路径和加载历程对砂岩的交替循环蠕变行为有显着影响。加载路径可以加速岩石样品中的损坏，这可以通过损坏样品中发生的更大塑性应变和较少损坏样品的蠕变行为中更大的粘性应变来证明。加载历史会增加损坏样品的粘性应变和塑性应变。由不稳定裂纹阈值确定的最大和最小加载应力提供了岩石样品中不稳定裂纹扩展的基础。