The construction of the dual-direction
eight-lane open-cut tunnel on
Xinsen avenue in Chongqing, China, faces several challenges, including slow
progress, difficulties in precision control, and high construction costs. To
address these issues, an innovative inverted T-shaped
self-stabilizing composite joint is designed and developed.
Field tests are conducted to verify the load-bearing
capacity and reliability of the joint. Long-term
monitoring is implemented to evaluate the stress and strain in the concrete and
steel reinforcement, as well as the relative rotation and deformation of the
joint, in comparison to fully prefabricated joints. The findings are as
follows: (1) Backfilling above the arch and extended use significantly affect
structural performance. Notably, the adverse effects of early-stage backfilling on the composite joints diminish over time,
allowing a transition from localized to full-section
compression and thereby enhancing structural stability. (2) The incorporation
of annular reinforcement in the post-cast region of the
inverted T-shaped joint improves stress distribution in
the compression zone, thereby enhancing load-bearing
capacity. (3) Monitoring data
indicate that although the deformation trends of the self-stabilizing composite joint resemble those of fully prefabricated
joints, the magnitudes are smaller, resulting in improved load performance.
These results demonstrate that the self-stabilizing
composite joint structure offers notable advantages in improving construction
efficiency, reducing precision requirements, and ensuring reliable arch-top connections.
LIN Zhi
,
GOU Xiaoying
,
XU Zhanglong
,
HAI Dapeng
.
Mechanical Properties of Self-Stabilizing
Composite Joint in Arch
Structure of Large-Span Open-Cut
Tunnel
[J]. Tunnel Construction, 2025
, 45(4)
: 695
-707
.
DOI: 10.3973/j.issn.2096-4498.2025.04.004
