Thermomechanical Coupling Analysis of the Lining Structure of the Tunnel Entrance in Cold Regions Based on Peridynamics

Abstract

To explore the effect of frost heaving of the tunnel entrance in cold regions, this paper carries out a thermomechanical coupling analysis based on peridynamics (PD), combines PD with finite-element method (FEM) into a numerical model, and verifies the feasibility of the proposed model. On this basis, we selected frost heave amount as the quantitative index, discussed the evolution law of the energy field in the lining structure of the tunnel entrance in cold regions, and analyzed the stress of the lining structure, as well as the expansion and distribution laws of lining cracks, under different frost heave amounts. The results show that: The difference of frost heave amount indirectly brings changes to the system’s energy field. With the growth of frost heave amount, the thermal potential and strain would increase. During the changes, the thermal potential and strain energy of the system are both positively correlated with frost heave amount. The degradability of tunnel lining increases with the frost heave amount of the lining. A high density of cracks can be observed at the foot and waist of the arch, most of which are tensile cracks. With frost heave amount as the main temperature reference, this research explores the degradation state of the tunnel entrance in cold regions, which greatly facilitates the maintenance, repair, and safe operation of tunnels.