To investigate the control effect of negative
Poisson′s ratio(NPR) anchor cable on
large deformation of Dongmachang tunnel in soft rock across faults, static
tensile experiments are conducted on the NPR anchor cable to validate their
constant resistance to large deformations and their effectiveness in resisting
external forces. Subsequent experiments on three-dimensional
physical modeling of NPR anchor cable for deformation control of the
surrounding rock in the Dongmachang tunnel. The experimental phenomena and
results show the following: (1) In the excavation process, the tunnel
surrounding rocks exhibit no large collapse, indicating that the NPR anchor
cable has a better support effect on the soft rock tunnel surrounding rocks.
(2) After loading, the maximum displacement of the surrounding rock at nonfaulted section after using NPR anchor cable is approximately 14 mm,
and that at faulted section is approximately 21 mm. The irregularity of the
stress distribution applied to the tunnel area leads to extrusion and
deformation of the tunnel surrounding rock with an oscillating displacement
curve. (3) Under the support of NPR anchor cable, the maximum surrounding rock
stress occurs at the left arch shoulder, and the maximum shear stress occurs at
3 cm on free face (reaching 0.3 MPa). Large-scale
asymmetric damage does not appear in the tunnel, and the general deformation
can be controlled.
TAO Zhigang, LIN Weijun, LI Yong, SUN Yingying, XIONG Yiwen, CHEN Mingliang
. Control Technology of
Negative Poisson′s Ratio Anchor Cable for Large Deformation Tunnel Across Faulted Soft Rocks[J]. Tunnel Construction, 2024
, 44(S1)
: 113
-123
.
DOI: 10.3973/j.issn.2096-4498.2024.S1.012
