The Tjoint has complex forces and is easy
to cause safety accidents. To investigate the weakening effect of the main
tunnel segment and ensure the safety of shield tunneling, a cutting test is
conducted on the shield cutterhead used in mechanical connection channel, the
excavation and cutting process of the concrete segment at the launching end is
simulated, and the change of the cutting force of the tool at different moments
and relationship curve and the distribution law of internal forces of segments
and bolts under different working conditions are revealed. The following
conclusions are obtained: (1) The
greater the cutting thickness and speed of the tool, the greater the cutting
resistance, the more obvious cracking of the concrete and the serious tool
wear. The greater the strength of the base concrete, the less damage to the
surface of the concrete during cutting. (2) The cutting of tube segments has a
greater impact on the bolts of a same ring, and less impact on the bolts on the
side. As the cutterhead rotates and advances, the displacement of the tube
segments changes, and the displacement of the bolt connection points gradually
increases. When the cutterhead drills out of the segment, the displacement of
the concrete segment and the internal bolt gradually stabilizes. (3) Changing
the strength needed to cut the segment has little effect on the deformation of
the tunnel. After changing the cutting strength, the displacement of the tunnel
segment increases, but the influence is relatively little, and the structure is
still in safe.
HUANG Yi, LIU Zhenghao, MA Xianfeng, ZHU Yaohong, DONG Zibo
. Research on Cutting Test and Numerical Simulation of Segments
Used in Connection Passage with Mechanical Excavation Method[J]. Tunnel Construction, 2022
, 42(S1)
: 93
-103
.
DOI: 10.3973/j.issn.2096-4498.2022.S1.011
