为探究排水系统结晶堵塞对盐岩地区半包排水隧道的衬砌孔隙水压力和结构力学响应特征的影响规律，并为易结晶堵塞隧道建设提供设计参考，对云南省内3座公路隧道的堵塞情况进行调研，基于现场调研结果，利用FLAC3D软件建立半包排水系统隧道模型，对比不同排水单元对称与非对称堵塞下隧道衬砌结构力学响应。研究结果表明： 1）盐岩地区隧道排水管碳酸钙结晶堵塞首先发生在排水管件连接部位，随后向各管道逐渐发展。2）随着对称和非对称堵塞排水单元数量增加，衬砌最大孔隙水压力符合Logistic回归模型。当堵塞单元数超过3个时，最大孔隙水压力趋于稳定，堵塞影响范围仍持续扩大。3）半包排水隧道衬砌的最大孔隙水压力均位于仰拱段，对称堵塞时位于堵塞中心断面的仰拱中点，非对称堵塞时位于堵塞中心2个排水单元之间靠近堵塞一侧仰拱段。隧道堵塞后衬砌拱脚处孔隙水压力增幅均最大，大于150%。4）不同排水单元对称或非对称堵塞时，仰拱中点的最大主应力基本保持不变，其他位置的最大主应力和最小主应力均显著增加。与对称堵塞相比，非对称堵塞时最小主应力增幅最大的位置从拱肩移至拱腰处。
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.
