Stability Analysis of Surrounding Rock in Deep Underground Engineering Under Fluid-solid Interaction

Abstract

The geological environment of deep rock masses is extreme and complex, characterized by typical deep geological features such as high geostress, high permeation water pressure, and high geotemperature. Geological disasters like water and mud inrush, high-intensity rock bursts, and large-volume collapses occur frequently in engineering construction, presenting more complex mechanisms of disaster than shallower rock masses and severely impacting the construction and operational safety of deep underground projects. Utilizing three-dimensional numerical simulation methods, this study investigated the deformation, stress, and plastic zone characteristics of surrounding rock under multi-field coupling conditions during the construction of deep caverns, revealing the stability influencing factors of deep caverns under multi-field coupling. A funnel-shaped precipitation area forms near the excavation surface of the cavern, gradually expanding as the initial pore water pressure increases. The concentration of seepage vectors in the sidewalls and arch feet continues to increase, with local seepage rates reaching 5.1×10^-6. The cavern's crown and sidewalls are particularly sensitive to changes in pore water pressure, with the maximum tensile stress appearing 1 m and 3 m axially along the sidewalls of the cavern. The plastic zone experiences its greatest increase at a water pressure of 4 MPa.