To study the seismic dynamic response of overlapped
tunnels crossing through landslide body, a 1∶100 vibration platform test is
conducted. The dynamic strain and acceleration are used to evaluate the dynamic
response of tunnel lining and analyze the dynamic response of surrounding rock
respectively, and then the fast Fourier transform and wavelet packet are used
to discuss the spectrum response. The results show the following: (1) The
sensitivities of the overlapped tunnels′ lining
structures to the seismic waves vary. The strain response of the outer surface
of the tunnel lining mainly occurrs at the right arch waist and left arch foot.
However, the damage of the inner surface of the upper tunnel lining is mainly
in the left arch waist, while the damage of the lower tunnel lining is mainly
in the right arch waist. The stresses on the inner and outer surfaces of tunnel
lining vary, which will easily induce lining damage. (2) The upper tunnel
structure has a certain amplification effect on the seismic wave when the
ground motion input is large (0.3g~0.6g), and the
acceleration response of each measuring point has an obvious amplification
effect along the elevation direction. Furthermore, the acceleration response of
the crown and invert of the upper tunnel is greater than that of the lower
tunnel, indicating that the upper tunnel should be the focus of attention in
the process of earthquake resistant design. (3) The crown and invert of the
tunnels are mainly affected by the seismic waves in the 1st2nd frequency band (0.20~12.52 Hz), while the seismic waves above
25.02 Hz have little impact on the overlapped tunnels. Additionally, the band
energy distribution characteristics of the upper and lower tunnels are
significantly different.
SUN Tianzuo, LEI Hao, WU Honggang, GAO Yan, LI Dezhu, SUN Tianyou
. Seismic Dynamic Response of Overlapped Tunnels Crossing
through Landslide Body[J]. Tunnel Construction, 2021
, 41(S2)
: 180
-189
.
DOI: 10.3973/j.issn.2096-4498.2021.S2.023
