Research on the Zoning Fracture Range of Deep Surrounding Rock under Thermal-Force Coupling Effect

In order to address the problem of the influence of multi-field coupling in high-ground stress areas on the rupture range of deep-seated surrounding rocks, a mechanical analysis model of the plastic zone of surrounding rocks under multi-field coupling is established based on the double-shear unified strength theory, and a formula for calculating the radius of the plastic zone of surrounding rocks in deeply buried tunnels under the action of heat-force coupling is proposed. On this basis, the rupture zone radius calculation formula for the rupture of surrounding rocks in deeply buried tunnels under the action of heat-force coupling is further proposed. Combined with the analysis of engineering examples, it can be seen that, under the action of heat-force coupling, the error of the fracture radius of the surrounding rock zoning calculated based on the double-shear unified strength theory is less than 8.9%, which proves the reasonableness and feasibility of the calculation method proposed in this paper. The research results provide a theoretical basis for the analysis of the stability of the surrounding rock under the influence of high ground stress and high ground temperature and also provide a new method and means to quantitatively describe the phenomenon of zonal rupture.