Application of Artificial Ground Freezing Technology in Modern Urban Underground Engineering

Abstract

Based on typical water-rich sandy gravel strata in Beijing, in order to explore the application of the artificial ground freezing method (AGF) in urban large-scale underground engineering, the formation and development of freezing body were analyzed when multirow freezing pipes were working together, and the group effect exhibited during the freezing process was also revealed in this paper. On this basis, the basin-shaped freezing method (BFM) is put forward as an application of AGF used in underground engineering. BFM structure consists of two parts: the frozen curtain (basin wall) around the excavation scope and the horizontal frozen body (basin bottom) at the bottom of the station. Physical model test and numerical simulation were conducted to study temperature field expansion of BFM under two different conditions. The results show the following: (1) The group effect refers to the cooling effect of different freezing pipes influencing each other during freezing process. Under the condition of still water, the group effect expands the freezing area, and it shows the gradual development of freezing from back water surface to front water surface under seepage condition. (2) BFM can effectively play the role of water proofing, and although different parts of basin structure show different frozen order under different conditions, both basin wall and basin bottom can form an effective thickness during the freezing process.

Artificial Thawing of Frozen Ground: A Review

“…In contrast to the relatively sparse amount of studies concerning artificial ground thawing, there is an abundance of studies and mathematical models covering frost action and artificial ground freezing, that is, the reverse process (Alzoubi et al 2017;Blanchard and Fremond 1985;Bronfenbrener 2009;Bronfenbrener and Bronfenbrener 2010;Brown and Payne 1990;Mackay et al 1992;Naaktgeboren 2006;Nixon 1990;Qi et al 2020;Rouabhi et al 2018;Yan et al 2019;Yokoo et al 2005;Zhou et al 2009Zhou et al , 2021. However, many such models cannot be directly applied for accurately predicting thaw depth.…”

Numerical simulation of temperature field of a new type of freezing device under seepage effect

“…Artificial freezing technology was proposed by a German engineer in the 1860s and was initially applied in mine excavation for mining coal [ 1 , 2 ]. It has been widely used abroad due to its advantages of safety, flexibility and efficiency [ 3 ]. Since the 20th century, many countries have used artificial ground freezing technology in engineering fields such as subways, tunnels and coal mines, and have accumulated a lot of experience [ 4 – 8 ].…”

Model Test and Numerical Simulation Analysis on Freezing Effect of Different Freezers in Freeze-Sealing Pipe-Roof Method

“…Four mainstream methods can be used to study these problems; they are theoretical analysis, numerical simulation, model test, and field monitoring. Qi et al [15] studied the temperature field expansion of basinshaped freezing method through physical model test and numerical simulation; it shows the gradual development of freezing from backwater surface to front water surface under seepage condition. Liu et al [16] studied the freezing effect considering the pipe inclination in the unit cell model by prescribing various values of freeze pipe spacing based on a coupled thermohydraulic finite element method.…”