Numerical Analysis on the Temperature Field of Freezing Reinforcement with Vertical Freezing Plate at the End of Shield Tunnel

In our report, in order to explore the effects of freezing and strengthening of the vertical freezing plate at the end of shield tunnel and optimize the scheme of freezing and strengthening of the plate, firstly, the freezing strengthening structure of the vertical freezing plate at the end of shield tunnel was introduced; secondly, USES finite element software was used to analyze the development law of the temperature field of the freezing strengthening of the vertical freezing plate by numerical modeling. The results showed that the thickness of the freezing plate has little influence on the final freezing effects, and the best thickness is 200 mm.The increasing of the distance between the freezing plate and the geodesy can significantly increase the final effective freezing thickness, however, too large a freezing distance will result in poor freezing effects of the soil near the geodesy, the optimal distance is 800 mm. Path 4 and path 5 is located on the left side and the right side of the freezing plate, respectively, with a distance of 800 mm from the freezing plate.However, the final freezing effects and cooling process of the two paths are significantly different. The reason is that path 5 is the path on the contact surface between soil and the geodesic wall, and the soil surface is set as adiabatic during the temperature field simulation, low temperature accumulates rapidly on the surface of path 5 without diffusion, the soil around path 4 is not adiabatic.