The modal analysis and
vibration response of prefabricated middle partition walls in large-diameter shield tunnels under train vibration load and aerodynamic
load are investigated. Numerical simulation methods based on fluid mechanics
calculation software are used to systematically examine the influence of single-vehicle travel and double-vehicle
intersection on the aerodynamic effects of the middle partition wall, obtaining
aerodynamic load time-history curves. In addition, the
dynamic finite element method is utilized to analyze the modal vibration mode
and vibration response of the prefabricated middle partition walls. The results
reveal the following: (1) When a single train travels at a speed of 160 km/h,
the pressure changes at each measuring point in the tunnel are consistent, with
the maximum pressure occurring at the monitoring point of 1/3 tunnel length
from entrance. When two trains intersect, the pressure amplitude on both sides
of the partition wall changes inconsistently, leading to differences in the
pressure curves. (2) As the burial depth of the tunnel increases, the bending
modal frequency of the middle partition wall slightly decreases, and the
vertical displacement response is significantly stronger than the horizontal
displacement response. The frequency corresponding to the first-order bending mode of the prefabricated middle partition wall ranges
between 16.106 6 and 17.141 9 Hz, differing from the main frequency range of 0－2 Hz observed in the tunnel wall during on-site
testing. This indicates that the prefabricated middle partition wall poses no
resonance risk under fixed constraint. (3) The vibration effect of the middle
partition wall is primarily influenced by the train load, whereas the
aerodynamic load has a relatively minor impact on the vibration response.
CHEN Yangxun
,
XIAO Mingqing
,
XUE Guangqiao
,
ZHANG Di
. Vibration Response
Characteristics of Prefabricated Middle Partition
Walls in Large-Diameter Shield Tunnels[J]. Tunnel Construction, 2024
, 44(12)
: 2376
-2384
.
DOI: 10.3973/j.issn.2096-4498.2024.12.007
