Key Technologies for Applying Liquid Nitrogen Freezing to Rescue Stuck Pipe Jacking Machines

Liquid nitrogen reinforcement technology is characterized by several distinct advantages, including high freezing velocity and high strength, rendering it an essential method for engineering accident rescue and emergency response. This article examines the escape of the dolly-mounted jack during the third phase expansion project of Guangzhou Baiyun International Airport. The design of the scheme, critical construction technologies, and the application effects of liquid nitrogen freezing reinforcement technology was introduced. The study proposes three critical technical measures to the rescue engineering characteristics: a drill bit prediction method for strata containing metal debris, temperature control measures for the dolly-mounted jack, and frost heave deformation control measures. Which ensure that no sudden bit failure occurs during drilling, and the maximum frost heave deformation is controlled within 3 mm. Furthermore, the analysis of temperature measurement data from various depths and positions of the frozen reinforcements highlights the unevenness of liquid nitrogen reinforcement technology. It emphasizes the necessity of employing a comprehensive evaluation method of multi-section temperature fields for liquid nitrogen reinforcement projects. The findings of this research can serve as a valuable reference for similar future projects.