A Voronoi tessellated model considering damage evolution for modeling meso-mechanical mechanism of the sandstone

The strength of sandstone samples considering different particle sizes is required in many engineering applica-tions. A rock model based on the Voronoi tessellated model is established for studying the failure mechanism of sandstone samples. Uniaxial compression, Brazilian splitting and triaxial compression tests are carried out to evaluate the influence of different crystal sizes on macroscopic parameters of sandstone. The uniaxial compressive strength, elastic modulus and tensile strength of the specimens show an increasing trend with the decrease in the crystal size. Failure with redistributed stress has been observed, and strain energy density (SED) can help explain the failure mechanisms. Additionally, a constitutive model is compiled to reproduce the damage evolution taking into account the heterogeneity in elastic modulus and rock strength, which is in good agreement with the experimental results. In the engineering application, it is found that the damage on the surface of the slope is triggered by the action of vibration excitation. The dynamic response of the slope is more intense if the vibration frequency reaches its optimal frequency. The proposed constitutive model is used to quantitatively evaluate the accumulation of damage of the Mining-by tunnel. This work is anticipated to be extensively utilized in other engineering applications.

Automated summary

The influence of crystal size on the macroscopic parameters of sandstone samples is studied using a rock model based on the Voronoi tessellated model. It is found that decreasing crystal size results in increased strength and elastic modulus. Strain energy density (SED) is shown to help explain the failure mechanisms of the sandstone samples. A constitutive model that considers the heterogeneity in elastic modulus and rock strength is developed and is in good agreement with experimental results. The study also identifies the triggering of surface damage on slopes by vibration excitation in engineering applications as well as proposes a constitutive model for quantitatively evaluating damage accumulation in mining tunnels.