The Damage Deterioration Mechanism of Tunnel Structure under the Effect of Thermo-Mechanical Coupling and Its Maintenance

Abstract

The effect of thermo-mechanical coupling is a key factor that needs to be fully considered during the construction, operation, and maintenance of tunnels in high ground temperature areas so that measures could be taken to reduce the frequency of damages and accidents. However, research methods and theoretical results for tunnel support structures under high temperature conditions and layered soft rock environment are insufficient, therefore, to fill in this research blank, this paper aims to study the damage deterioration mechanism of tunnel structure under thermo-mechanical coupling effect and its maintenance. In the second chapter, this paper gave a diagram showing the coupling mechanism of several physical fields, including the stress field, the seepage field, and the temperature field, and proposed control equations for the coupling of these fields during the damage deterioration process of the tunnel structure. In the third chapter, this paper applied two yield failure criterions, namely the Mohr-Coulomb criterion and the maximum tensile stress strength criterion to the analysis of the evolution of compression shear failure and tensile failure, and built scientific evolution equations for the permeability coefficient and the thermal conductivity coefficient. At last, experimental results verified the effectiveness of the constructed model and the analysis method.