Fluent software is employed
to simulate the wind velocity and dust concentration fields during shotcreting
and mucking in a tunnel to clarify the influence of environmental parameters,
such as air pressure, on dust transportation and explore the dust concentration
distribution during crucial dust-producing
processes in high-altitude tunnel spaces. The impact of
altitude on the airflow and dust concentration fluctuations in the tunnel is
then analyzed. A dust concentration prediction model is established by fitting
the wind velocity and dust concentration distribution along the tunnel. A
linear regression equation is constructed to relate altitude to wind velocity
and dust concentration distributionnonuniformity
parameters. The research results demonstrate the following: (1) In areas of
high altitude, the dust transport speed during ventilation reaching wind speed
is longer than that of plain areas. In low-altitude
areas, the airflow is nearly linear and flows out of the tunnel along the
entire cross-section. As the altitude increases, the
coverage range of the airflow gradually decreases, and the airflow along the
tunnel moves in an S shape. (2) During shotcreting, the wind speed is higher
within 40 m from the tunnel face; it lowers rapidly when the distance from the
tunnel face is more than 40 m, and it uniformly fluctuates when the distance
from the tunnel face is between 60 and 180 m. The overall dust concentration
within the tunnel fluctuates with increasing altitude, decreasing uniformly
between 20 and 180 m from the tunnel face and approximately linearly. (3)
During mucking, the average wind speed and dust concentration of the entire
cross-section remain unchanged with increasing
altitude, whereas the nonuniformity of the wind speed and dust concentration
increases linearly. For every 1 000 m increase in altitude, the nonuniformity
of wind speed and dust concentration increases by 0.156 m2/s2 and 4.42×10-6 kg/m3,
respectively.
MA Guodong
,
HUANG Jiaxun
,
WANG Dong
,
YIN Long
,
ZHOU Chuanchuan
,
ZHANG Jiangshi
. Wind Velocity Field and
Dust Distribution Patterns During Shotcreting and Mucking in High-Altitude Tunnels[J]. Tunnel Construction, 2024
, 44(6)
: 1241
-1250
.
DOI: 10.3973/j.issn.2096-4498.2024.06.011
