Study on the Mechanical Properties of Hydraulic Tunnels With High Ground Temperature and the Temporal and Spatial Evolution of Plastic Zone

In order to explore the temporal and spatial evolution of the mechanical characteristics of hydraulic tunnels with high ground temperature during construction, a numerical simulation study was performed on the construction process of the tunnel using finite element calculation software, and the results were compared with the field monitoring results. The results showed that the displacements of the top arch and waist arch of the tunnel increased with time, and the top arch of the tunnel entrance was greatly affected by the excavation. The plastic zone was larger in the top arch and the bottom arch of surrounding rock, and smaller in the waist arch. The plastic strain of the top arch and bottom arch of surrounding rock was smaller, while the plastic strain of the waist arch was larger. The parallel excavation and lining construction have less impact on the surrounding rock.