When the tunnel passes through the hourglassshaped
karst in Wuhan area, the karst treatment range will directly affect the project
safety and investment. The analysis and research of karst collapse angle are
carried out to quantify the karst treatment area. Firstly, the model test is
adopted to simulate the process of karst collapse to verify the mechanism of
seepage liquefaction collapse of saturated sandy soil; the sand loss and
collapse angle are researched quantitatively; and the collapse angle is
calculated to be 35.8°. And then, the deformation
morphology of the tunnel is analyzed by numerical simulation of karst collapse
process under 5 working conditions; the minimum safety distance between tunnel
and karst cave is determined based on the tunnel deformation control standards,
and the karst collapse angle is calculated to be 33.9 °.
Finally, comparison is made on karst collapse angle between model test and
numerical calculation, and the conclusion that the collapse angle of hourglassshaped karst is similar to the friction angle of sand soil and the
collapse angle is 1 ~ 3 ° larger than internal friction
angle is obtained. The research results are applied to the hourglassshaped karst treatment of Wuhan Metro Line 6, and the collapse angle
is taken as 35° to calculate the karst treatment range.
According to this scheme, the shield passed through the karst area smoothly.
LI Shenkui
. Numerical Analysis and Model Test of Hourglassshaped
Karst Collapse in Wuhan Area[J]. Tunnel Construction, 2020
, 40(7)
: 981
-987
.
DOI: 10.3973/j.issn.2096-4498.2020.07.006
