When the tunnel crosses fractured zone and faults,
overlarge tunnel structural deformation and even collapse often occur. As a
result, the onsite monitoring data of a deepburied tunnel
lining crossing fractured zone in southwest China are analyzed. And based on
numerical simulation experiments, the laws of tunnel crown settlement and
peripheral convergence are studied, and comparison is made between the two
laws. The results show: (1) Uneven settlement occurs to the transition zone
between Grade Ⅳ and Ⅴ surrounding rocks, and the settlement of Grade Ⅴ surrounding rock is 15 mm larger than that of Grade Ⅳ surrounding rock. (2) The settlement of tunnel crown is about 1.25~1.75 times
of the peripheral convergent displacement, which indicates that the sensitivity
of the tunnel crown to the uneven settlement is greater than peripheral area,
and the tunnel crown is the weak part of the tunnel structure. Based on the
selfdeveloped twoway sliding
physical model box, the deformation properties of lining under the condition of
uneven settlement are studied. The study results show that the tunnel lining
deformation under uneven settlement can be roughly divided into five stages,
i.e. elastic strain stage, soil compactionattitude
adjustment stage, plastic strain stage, soil recompactionattitude adjustment stage, and fracture failure stage; the tunnel
crown axial deformation of each section is about 1.75~2.45 times of the
peripheral convergence, which also shows that the sensitivity of the tunnel
crown to environmental variation is greater than that of peripheral
convergence, and monitoring and protection should be carried out for tunnel
crown.
WANG Fei, GAO Mingzhong, LIN Wenming, CHEN Hailiang, WANG Mingyao, LU Tong
.
Study on the Deformation Law of Deepburied
Tunnel Lining
Crossing Fractured Zone
[J]. Tunnel Construction, 2020
, 40(S1)
: 232
-240
.
DOI: 10.3973/j.issn.2096-4498.2020.S1.029
