In order to study the
influence of effects of temperature field distribution in railway tunnels in
cold regions on their anti-freeze
design, 5 typical tunnels are selected from 3 operating railway projects in
high latitude severe cold regions to test and study the temperature field
distribution law in tunnels. On this basis, effects of temperature field
distribution in tunnels in cold regions are put forward, and the optimization
of anti-freeze design of high altitude portals is
preliminarily analyzed according to the temperature field distribution law in
tunnels. The research results show that: (1) In winter, the temperature field
distribution in tunnels in cold regions has obvious chimney effect, shielding
effect, scale effect, and cold bridge effect. (2) When railway tunnels are
subject to thermal potential difference, static pressure difference between
portals, and atmospheric natural wind pressure, the static pressure difference
between portals dominates and produces obvious chimney effect. In winter, there
is obvious non-uniformity in the longitudinal
distribution of air temperature in long railway tunnels in cold regions,
resulting in continuous flow of cold air outside tunnel from low altitude
portal to high altitude portal, which intensifies the heat exchange between inside
and outside tunnel. (3) For tunnels whose alignment intersects the prevailing
winter wind direction at a large angle, the ratio of their static pressure
difference between portals to thermal potential difference during the winter testing
period is half of that of tunnels whose alignment is basically consistent with
the prevailing winter wind direction. This indicates that it is beneficial for
thermal insulation and anti-freezing of tunnels if
their alignment is perpendicular to or intersects the prevailing winter wind
direction at a large angle in cold regions. (4) For long "double spur
grade" railway tunnels in cold regions, the anti-freeze
protection length at the high altitude portal can be shorter than that at the
low altitude portal. For long single-slope railway
tunnels in cold regions, the anti-freeze protection
measures for the high altitude portal can be weaker than those for the low
altitude portal.
MA Zhifu
,
TIAN Siming
,
YANG Changxian
,
WANG Wei
,
WANG Jiawei
. Study on Effects of
Temperature Field Distribution in Railway Tunnels
in Cold Regions and Countermeasures[J]. Tunnel Construction, 2024
, 44(12)
: 2332
-2349
.
DOI: 10.3973/j.issn.2096-4498.2024.12.00
