ZHOU Haizuo , LIU Lingxia , SHI Zhuohang , HU Jun , LI Chenghu2, XIA Boyang , ZHANG Jingjing , WANG Shanxing , JIANG Xuejun
Journal of Glaciology and Geocryology.
Online available: 2025-08-13
Artificial ground freezing (AGF) is a geotechnical technique widely used in underground construc⁃
tion. It provides temporary stabilization of the soil by freezing the pore water to form a “frozen wall” with suffi⁃
cient strength and impermeability. This technique is crucial in applications such as foundation pit excavation,
shaft sinking, and tunnel excavation, as it can effectively prevent groundwater infiltration, support surrounding
strata, and reduce the risk of soil collapse. However, groundwater seepage significantly disrupts the heat con⁃
duction mechanism during freezing, leading to a series of critical engineering issues such as redistribution of the
temperature field, irregular development of the frozen wall, and increased risk of frost heave deformation at the
surface. These issues may eventually cause construction delays, compromise structural stability, and even pose
potential threats to surrounding buildings and infrastructure, thereby posing major engineering risks. The influ⁃
ence of groundwater seepage on AGF mainly manifests in three aspects:(1) uneven temperature distribution;
(2) irregular development of the frozen wall; and (3) increased risk of frost heave deformation at the surface.
First, the convective heat transfer caused by groundwater flow disrupts the temperature gradient distribution that
originally relies on heat conduction, resulting in an increased temperature difference between the upstream and
downstream sides of the frozen wall. Second, as the freezing front on the upstream side develops slowly due to
the obstruction caused by seepage, the frozen wall may exhibit asymmetric growth, thereby weakening its over⁃
all structural strength. Third, frost heave deformation is closely related to water migration. Groundwater seep⁃
age transports unfrozen water into the freezing zone, where it crystallizes and causes heave deformation within
the soil matrix. If not properly controlled, surface uplift may exceed the warning thresholds specified in engi⁃
neering codes, potentially damaging surrounding buildings. To thoroughly investigate and address the above is⁃
sues, this study established a numerical model on the COMSOL Multiphysics platform, which enabled the cou⁃
pled simulation of multiple physical processes of heat conduction, fluid flow, and mechanical deformation. The
core objective of this model was to investigate the spatiotemporal evolution patterns of soil temperature and defor⁃
mation fields during the AGF under different groundwater seepage velocities. By systematically analyzing the in⁃
fluence of groundwater seepage on the formation and evolution of the frozen wall, as well as the mechanisms af⁃
fecting frost heave deformation at the surface, this study revealed the complex regulatory effects of groundwater
flow on the freezing process. The results showed that groundwater seepage significantly increased the tempera⁃
ture gradient between the upstream and downstream regions of the frozen wall. The development of the frozen
wall exhibited significant asymmetry because the freezing speed at the upstream front was strongly suppressed by
seepage. This asymmetry not only reduced the overall structural performance of the frozen wall but also extend⁃
ed the freezing duration. After construction was completed, the maximum frost heave deformation at the surface
may exceed the warning thresholds specified in relevant engineering standards, necessitating measures to prevent
damage to surrounding structures. To address this problem, this study proposed a non-uniform layout strategy
for freezing pipes, dynamically adjusting the spatial density based on the direction and velocity of groundwater
flow. This optimized layout significantly improved the efficiency of cold energy utilization, limited its migration
within the soil, promoted the uniform development of the frozen wall, and shortened the freezing duration. Un⁃
der high seepage velocity conditions (v=0. 8 m·d-1 ), the optimized model confirmed the effectiveness of this
strategy. After construction, the maximum surface frost heave deformation was controlled below the warning
threshold, preventing potential damage to surrounding buildings. By integrating numerical simulation with engi⁃
neering optimization strategies, this study provides theoretical support and practical guidance for the design and
implementation of AGF technology under groundwater seepage conditions. The findings highlight the impor⁃
tance of incorporating groundwater dynamics into AGF system design and provide feasible solutions to enhance
the safety and efficiency of underground engineering under complex hydrogeological conditions.