To further
understand the impact of karst sinkholes on structural safety of Jiguanshan
tunnel section from K72+220 to
K72+340, the collapse scale of the karst sinkhole sidewall is estimated by
combining the site survey results with the location and size of the underlying
karst cavity. And then numerical simulations of karst sinkhole collapse are
conducted by PFC3D to investigate the morphology of the karst sinkhole sidewall
after the collapse. Based on the collapse simulation results, a typical crosssection is selected to establish a twodimensional
finite difference model to analyze the impact of karst sinkhole’s collapse on the lining structural safety of Jiguanshan tunnel. The
results show the following. (1) The collapsing body at the sinkhole sidewall
will mainly load on the top of the karst cavity. The collapsed body volume is
approximately 16 000 m3, and the impact force derived
from the collapsed body is approximately 9.0×107 N. (2) The
maximum deformation of karst cavity top induced by collapse of the karst
sinkhole sidewall reaches 16 mm, which would make the safety factor of the
lining structure at the left wall and the arch foot of the left line be less
than 1.7. The overall average safety factor is still greater than the control standard,
indicating that the impact of collapse and accumulation on the safety of the
tunnel is limited.
WANG Zhanqiang
,
LI Tangjun
,
WAN Fei
. Impact of Karst Sinkhole Collapse on Structural Safety
of Jiguanshan Tunnel[J]. Tunnel Construction, 2020
, 40(S2)
: 100
-108
.
DOI: 10.3973/j.issn.2096-4498.2020.S2.013
