Mechanical Responses of a Deeply Buried Granite Exposed to Multilevel Uniaxial and Triaxial Cyclic Stresses: Insights into Deformation Behavior, Energy Dissipation, and Hysteresis

This article presents the results for cyclic uni/triaxial tests on the deeply seated granite samples drilled from a -915m deep tunnel in Sanshandao (SSD) gold mine. The monotonic and cyclic tests were carried out to observe the mechanical responses of the granite samples under different loading regimes. The disparities concerning the strain evolution and compressive strength of granite samples considering monotonic and cyclic uniaxial and triaxial loading are presented. Deformation behaviour, dissipated energy, and hysteresis are documented and evaluated. Quantitative correlations between strain evolution and cyclic stress levels are revealed. The amount of energy transformation during uniaxial and triaxial cyclic loading is determined. The impacts of confining pressure level on ultimate strain, energy dissipation, and stress-strain phase shift are presented. The mechanical responses of the granite samples subjected to different stress paths and loading strategies are summarised, and corresponding interpretations are given to clarify the differences of mechanical behaviour encountered in distinct loading methods.

Automated summary

This study investigates the mechanical responses of deeply seated granite samples through uni/triaxial cyclic tests, highlighting disparities in strain evolution and compressive strength under different loading conditions, as well as the relationships between deformation behavior, dissipated energy, and hysteresis. It also reveals quantitative correlations between strain evolution and cyclic stress levels, determines energy transformation during cyclic loading, and discusses the impacts of confining pressure level on ultimate strain, energy dissipation, and stress-strain phase shift. The mechanical responses of the granite samples subjected to different stress paths and loading strategies are summarized and explained to clarify the discrepancies in mechanical behavior encountered in distinct loading methods.