保持加载下岩石变形记忆效应时效特征规律研究

Deformation memory effect(DME), as one of basic properties of rocks, has time features. The influence of the loading time(T_c) on DME is one of time effects. Sandstone and two kinds of granite materials were selected to carry out physical experiments under different T_c. The accuracy of memory formation and the magnitude of strain difference were analyzed. Based on the viscoelastic frictional sliding theory of multi-microstructural planes in rocks, a basic memory theoretical model was constructed by using three elements of rocks, and the DME mechanical theory under different T_c was studied. The results show that, with increasing T_c, the accuracy of memory formation of granite and sandstone is obviously improved and the amplitude of strain difference decreases gradually, and that both the accuracy of memory and the amplitude of strain difference tend to remain unchanged when T_c increases to a certain extent. It is put forward that T_c is the optimum creep time when the amplitude of strain difference keeps stable. The variations of the memory formation accuracy and the strain difference amplitude obtained from the proposed theoretical model are consistent with physical experiment results, which means the proposed model based on multi-microstructural planes can describe the macroscopic behaviors of rock DME under different T_c. The research provides an experimental and theoretical basis for the study of rock DME.