Abstract: To investigate the evolution of the temperature field in asymmetric freezing reinforcement for underground large-diameter shield docking, a freezing model is constructed based on similarity theory to analyze the large-diameter shield docking project of the Jiangyin-Jingjiang Yangtze River Tunnel. The scale model tests show that under the action of externally distributed freezing pipes around the shield, the frozen wall closes to form a sealed freezing curtain after 20 days of freezing. At 70 and 160 days, the thickness of the frozen wall at the docking location reaches 3.9 and 6.0 m, with average temperatures of －13.4 °C and －14.7 °C, respectively. The development rates of the frozen soil on the advance shield side, follow-up shield side, and docking cross-section are similar. The volume of soil inside the freezing pipes affects the progression of the frozen-wall thickness and average temperature. After 100 days of freezing, the temperature change within the inner frozen soil becomes minimal, causing the overall thickness and average temperature of the frozen wall to stabilize. The thermal conductivity of the shield steel shell promotes freezing at the interface between the shield and soil, resulting in comparable freezing effects in both the circumferential and axial directions of the shield. At the end of the freezing process, the temperature on the shield shell surface reaches －17.6 ℃, reducing the risk of groundwater seepage around the shell. The shield structure and the arrangement of freezing pipes significantly affect the formation of the frozen wall and the temperature-field distribution. By optimizing construction parameters such as the drilling angle and the length of the freezing pipes, efficient bearing capacity and effective water-sealing performance can be achieved at the shield-docking location.

Key words: artificial ground freezing, shield docking, asymmetric freezing mode, freezing temperature field, distribution characteristics, scale model test