Damage Constitutive and Failure Prediction of Artificial Single-Joint Sandstone Based on Acoustic Emission

Abstract

The effect law of deformation and failure of a jointed rock mass is essential for underground engineering safety and stability evaluation. In order to study the evolution mechanism and precursory characteristics of instability and failure of jointed rock masses, uniaxial compression and acoustic emission (AE) tests are conducted on sandstones with different joint dip angles. To simulate the mechanical behavior of the rock, a jointed rock mass damage constitutive model with AE characteristic parameters is created based on damage mechanics theory and taking into account the effect of rock mass structure and load coupling. To quantify the mechanism of rock instability, a cusp catastrophe model with AE characteristic parameters is created based on catastrophe theory. The results indicate that when the joint dip angle increases from 0° to 90°, the failure mechanism of sandstone shifts from tensile to shear, with 45° being the critical failure mode. Sandstone's compressive strength reduces initially and subsequently increases, resulting in a U-shaped distribution. The developed damage constitutive model's theoretical curve closely matches the test curve, indicating that the model can reasonably describe the damage evolution of sandstone. The cusp catastrophe model has a high forecast accuracy, and when combined with the damage constitutive model, the prediction accuracy can be increased further. The research results can provide theoretical guidance for the safety and stability evaluation of underground engineering.

Mechanical Properties of Rock Specimens Containing Pre-Existing Cracks with Different Dip Angles Based on Energy Theory and Cohesive Element Method

“…Yuan et al [7] investigated the impact of the crack dip angle on the mechanical properties and failure modes of pre-cracked red sandstone in underground engineering, revealing a five-stage stress-strain curve and an increase in peak strength with the crack dip angle. Sun et al [8] conducted uniaxial compression and acoustic emission tests on sandstones with different joint dip angles, revealing a shift in the failure mechanism from tensile to shear with a critical angle of 45 • . Peng et al [9] studied the influence of crack dip angles on the energy characteristics of sandstones, showing that larger crack dip angles correspond to a higher energy storage but lower energy dissipation in rocks, explaining the enhanced bearing capacity with larger crack dip angles from an energy perspective.…”