Analysis on the evolution law of creep-fatigue failure energy of deep anchored jointed rock mass

Abstract

In order to explore the mechanical properties of deep rock masses under disturbance loads such as blasting and excavation, laboratory tests of anchored rock masses under creep-fatigue loads were carried out, and the law of energy evolution was further explored. The results show that: (1) Under the action of fatigue load, the area of the anchored jointed rock mass is smaller than the of the unanchored condition. When prestress is applied, the hysteresis area of the jointed rock mass is greatly reduced, indicating that the anchored prestress can effectively reduce its energy loss. (2) The higher the rock strength, the smaller the hysteresis loop area, the smaller the corresponding energy dissipation. Conversely, the lower the rock strength, the larger the hysteresis loop area and the larger the corresponding energy dissipation. (3) Comparing different loading and unloading rates, experimental results show that during each level of cyclic loading, the greater the loading and unloading rate, the greater the corresponding strain value and tangent slope. Considering the effect of loading and unloading rate on the deterioration of jointed rock masses, based on the principle of strain equivalence, the peak damage constitutive equation of jointed rock masses is obtained, and the accuracy of the model is verified through experiments, which provides ideas for deep rock structure support.

Keywords

• shear creep
• hysteresis area
• loading unloading rate
• energy loss
• damage constitutive equation