To investigate the effect of effective lining bearing
thickness loss induced by severe corrosive environment and construction defects
on the tunnel structural safety, a twodimensional lining force
analytical solution model is established based on elastic foundation curved
beam theory and spatial state method. The Laplace numerical transformation is
used to solve the internal force and displacement at each position of the
lining, and the results are compared with that of the numerical model under the
same working conditions. The effective secondary lining thickness loss is
simulated by discounting the local secondary lining thickness and adjusting the
discount range. The results reveal the following: (1) Increasing the range and
degree of secondary lining thickness loss leads to a significant reduction in
the crosssectional bending moment at the thickness
loss. However, the change in axial force is small. (2) The influence of
secondary lining thickness loss on the safety coefficient is mainly
concentrated in the area near the thickness loss. As the loss range increases,
the bending moment in the thickness loss area shows a concave parabolic
decrease, and the safety coefficient experiences sudden drop, rebound, and
stability. (3) When the loss thickness is small, the safety coefficient is less
affected by the change in axial eccentricity, and the effective bearing
thickness is approximately linear. After the deterioration thickness continues
to increase, the gain in safety coefficient by reducing axial eccentricity
increases rapidly, and when it is greater than the deterioration benefit of the
bearing crosssectional area, the calculated safety
coefficient increases. However, there is a risk of local structural deformation
damage.
LIU Xinrong
,
ZHOU Weifeng
,
ZHOU Xiaohan
,
ZHUANG Yang
,
WANG Ziqiang
. Analytical Model of Tunnel Structure Safety Factor
Considering Effective Bearing Thickness of Secondary Lining[J]. Tunnel Construction, 2022
, 42(11)
: 1844
-1852
.
DOI: 10.3973/j.issn.2096-4498.2022.11.003
