Abstract
The contact mode of particles in weakly cemented mudstone (WCM) and the persistence of cemented materials, as well as the cemented particulate matter composed of them, lead to different mechanical response characteristics from general soft rock during loading, that is, rheological failure occurs under low stress. In order to study the creep characteristics and energy evolution characteristics of weakly cemented rock (WCR) in the western mining area of China, based on the triaxial graded loading creep test of WCR, the creep deformation and failure law of WCM under graded loading was studied, and the energy evolution characteristics of WCR in each creep stage were revealed by energy dissipation theory. The results show that with the increase of confining pressure, the fracture angle decreases, but the failure strength and volume expansion point show the opposite trend. In addition, due to the strong heterogeneity of WCR samples, the contact force between particles is different after loading, which makes the slip between particles and cements and then produces a completely different fracture form from other rocks. The energy growth in the deceleration and steady creep stages is mainly affected by the confining pressure. With the increase of confining pressure, the growth rate of dissipation energy Ud and total energy U gradually tends to be constant, but the growth rate of strain energy Ue remains at a high level. In the accelerated creep stage, the growth rate of strain energy Ue decreases rapidly, and the residual energy storage capacity does not change significantly with the increase of confining pressure. These results revealed the unique creep properties and energy evolution characteristics of the WCR, providing a theoretical basis for long-term stability control of roadways that are built with WCR.
Published Version
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