Squeezing deformation of
soft rock tunnels in layered biased strata is typically large and uneven.
Therefore, a novel yielding element based on a reserved deformable angle is
proposed. A three-dimensional detailed numerical
model is built to analyze the bearing characteristics and the support effect of
the yielding element under bias loading. To validate the feasibility of the
model, it is applied in the formation of the Ganzhuang tunnel of the China-Laos railway. The research results show the following: (1) The
deformation in the tunnel support under bias loading is dominated by bending
deformation. The traditional yielding element is prone to tensile damage under
the action of the bending moment. The yielding element with the reserved
deformable angle can effectively release the bending moment of the steel arch
and adapt to larger bending deformation. (2) Under bias loading, the overall
stress level of the steel arch with the yielding element is significantly
reduced, and the bearing capacity of the arch meets the strength requirements.
(3) The field application shows that after installation of the novel yield
element, tunnel deformation is controlled within the permissible range after 18
days of excavation; the stress concentration of the primary support is less
pronounced, and the steel arch is no longer damaged by bending.
ZHENG Keyue
,
SHI Chenghua
,
YANG Yi
,
LOU Yili
,
YU Guoliang
. Yielding Support Technology
With a Reserved Deformable Angle for Squeezing
Soft Rock Tunnels in Layered Biased Strata[J]. Tunnel Construction, 2024
, 44(10)
: 2058
-2068
.
DOI: 10.3973/j.issn.2096-4498.2024.10.014
