To investigate the influence of crystallization
blockages in drainage systems on pore water pressure and structural mechanical
responses in semi-enclosed drainage tunnels within
salt rock regions and to provide design references for the construction of
tunnels prone to crystallization blockages, the authors examine the blockage
conditions in three highway tunnels in Yunnan Province, China. Based on
crystallization material testing and on-site survey
results, a tunnel model with a semi-enclosed drainage
system is developed using FLAC3D software. The mechanical effects on the tunnel
lining under symmetric and asymmetric blockages in different drainage units are
compared and analyzed. The research findings indicate the following: (1) In
salt rock regions, calcium carbonate crystallization blockages in tunnel
drainage systems primarily occur at the connections between drainage pipe
components and then propagate along the pipes. (2) As the number of symmetric
and asymmetric blocked drainage units increases, the maximum pore water
pressure in the lining follows a Logistic regression model. When the number of
blocked units exceeds three, the maximum pore water pressure stabilizes,
although the area affected by the blockage continues to expand. (3) The maximum
pore water pressure in the lining of semi-enclosed
drainage tunnels is consistently located at the crown section. Under symmetric
blockage, it is located at the midpoint of the crown directly above the
blockage center, whereas under asymmetric blockage, it is located between two
drainage units near the side of the blockage. After tunnel blockage, the
increase in pore water pressure at the lining′s
springline is the most substantial, exceeding 150%. (4) Under symmetric and
asymmetric blockage of different drainage units, the maximum principal stress
at the crown midpoint remains relatively constant. However, the maximum and
minimum principal stresses at other locations show substantial increases.
Compared to symmetric blockage, under asymmetric blockage, the location of the maximum
increase in the minimum principal stress shifts from the arch shoulder to the
arch waist.
LIU Xinrong
,
LI Linpeng
,
ZHOU Xiaohan
,
WANG Yan
,
ZHU Pengcheng
,
WANG Lijun
,
DING Miao
. Influence of Different Blockage Conditions on Lining
Structures in Semi-Enclosed Drainage Salt Rock Tunnels[J]. Tunnel Construction, 2025
, 45(5)
: 861
-875
.
DOI: 10.3973/j.issn.2096-4498.2025.05.001
