Study on Mechanical Response and Stress Environment Characteristics of Rock Mass with Through-Going Discontinuities

As large-scale continuous geological weak planes widely developed in deep mines, through-going discontinuities have a significant impact on the distribution of deep rock mass stress fields and the deformation and failure modes of surrounding rock and are the core factors restricting the safe and efficient extraction of deep resources. In this paper, indoor tests and numerical analysis methods were adopted to study the mechanical strength evolution characteristics and displacement changes of monitoring points of rock mass with prefabricated through-going discontinuities under horizontal and vertical pressure conditions, and the influence laws of different structural thicknesses and distances on the stress characteristics of engineering cavities were obtained. The results show that the introduction of through-going discontinuities can significantly reduce the peak strength and elastic modulus of rock specimens and change the circumferential strain. The thickness, distance, and relative position of through-going discontinuities jointly determine the strength degradation characteristics of the specimens. The larger the structural thickness (3 mm, 5 mm, and 10 mm), the weaker the strength degradation effect; when the through-going discontinuities are located above the cavity, the degradation effect is more significant. The relative position between the structure and the cavity determines the overall level of the stress field, while the structural thickness and distance (20 mm, 25 mm, and 30 mm) regulate the stress distribution and transfer path. When the through-going discontinuities are located above the cavity, the vertical stress of the surrounding rock decreases significantly with the increase of thickness, the horizontal stress remains basically stable, and the overall presents a high stress concentration characteristic. When the through-going discontinuities are located below the cavity, the vertical stress of the surrounding rock is generally low and changes gently; the horizontal stress increases gradually with the increase of thickness, and the overall stress level is much lower than that of the upper working condition.