The authors examine the
influence of groundwater seepage on the spatio-temporal evolution of the freezing temperature field during frozen
shaft construction. Using field-measured data and
hydrothermally coupled numerical simulations from the Yuandian No. 2 coal mine
in the Linhuan mining area of the Huaibei coalfield, Anhui, China, they analyze
the spatio-temporal evolution in a sand-permeated formation. Control variable method is employed to examine
the effects of key parameters, including flow rate, freezing pipe spacing,
freezing pipe diameter, and brine temperature, on the temperature field.
Furthermore, a sensitivity analysis of the freezing temperature field is
conducted using gray correlation theory to quantify the influence of each
parameter. The key findings are summarized as follows: (1) During freezing
shaft construction, thermal disturbances caused by excavation and wall
construction significantly weaken the formation of the freezing wall along the
shaft side. Groundwater seepage creates a temperature gradient of 2 ℃－4 ℃ between the upstream and downstream
regions outside the freezing pipe arrangement circle. (2) Comparative analysis
between numerical simulations and field-measured data
confirms that incorporating soil freezing characteristic curve discrete test
data into the numerical software reliably reproduces the evolution of the
temperature field in the water-rich sand layer at a
depth of 135 m. (3) In the water-rich sand layer, the
freezing wall achieves closure after 30 days of freezing, with its effective
thickness exceeding 5 m by the 100th day. Notably, the temperature field along
the seepage exhibits significant heterogeneity, with pronounced differences in
temperature variations between the upstream and downstream sections of the
freezing wall. (4) Under singlefactor conditions,
variations in freezing pipe diameter and brine temperature affect the thickness
and asymmetry coefficient of the upstream freezing wall, with changes remaining
under 10%. However, alterations in freezing pipe spacing significantly impact
closure time, demonstrating a variation range exceeding 60%. (5) For flow rates
below 5 m/d, brine temperature has the greatest influence on closure time,
while freezing pipe spacing plays a key role in determining the thickness and
asymmetry coefficient of the upstream freezing wall. At flow rates exceeding 5
m/d, both closure time and the asymmetry coefficient are predominantly
influenced by flow rate, whereas freezing pipe spacing continues to have the
largest effect on wall thickness.
RONG Chuanxin
,
TU Zhuo
,
LONG Wei
,
ZHANG Runze
.
Spatio-Temporal Evolution Pattern and Sensitivity Analysis of Freezing Temperature Field of Shaft in Water-Rich Sand Layer With Groundwater Seepage
[J]. Tunnel Construction, 2025
, 45(2)
: 268
-283
.
DOI: 10.3973/j.issn.2096-4498.2025.02.003
