The integration of highway
and metro systems within a double-layer
shield tunnel presents several challenges, including layout design, structural
integrity, combined vibrations from vehicles and trains, and ventilation and
smoke extraction. A case study is conducted on the Jiluo road Yangtze river-crossing tunnel in Wuhan, China, and key design technologies for
double-layer shield tunnels are analyzed through
comprehensive comparison and 2.5-dimensional numerical simulations. The findings include: (1) The underground
space required for the highway-metro double-layer shield tunnel can be minimized by optimizing the layout of the
tunnel′s plane, longitudinal and horizontal cross-sections, and implementing specialized designs for wastewater pump
rooms and evacuation staircases. This approach enhances the cross-sectional utilization and allows for a reduction in the tunnel′s outer diameter. (2) The use of a semiprefabricated
and semi-cast segment combined with a nonclosed lining
structure improves the overall bearing capacity of the internal structure and
segment lining, significantly reducing riverbed erosion and deposition. (3) The
combined vibrations from automobiles and metro trains slightly affects the
tunnel, and the saturated fine sand stratum at the tunnel base remains stable
without liquefaction. (4) Segmented longitudinal flues in the metro tunnel
effectively manage smoke extraction over long sections without requiring air
shafts, facilitating evacuation and greatly reducing construction challenges.
(5) The inevitable cross-influence between highway and
metro operations necessitates advance study of management interfaces and
investment division to aid in effective decision-making.
XIAO Mingqing
,
SUN Wenhao
,
HE Yingdao
,
HU Weidong
. Key Design Technologies for
Integrated Highway-Metro Double-Layer Shield Tunnels[J]. Tunnel Construction, 2024
, 44(8)
: 1533
-1543
.
DOI: 10.3973/j.issn.2096-4498.2024.08.001
