River-crossing tunnels in mountainous cities face numerous challenges,
including significant terrain elevation differences, complex geological conditions,
and densely built urban environments. The authors examine the Yangtze river
tunnel of the Chongqing-Hunan high-speed railway in Chongqing, China, focusing on the project′s topography, hydrogeology, and surrounding urban setting. A
multidimensional technical comparison and innovative design process are
undertaken to optimize the route alignment, excavation scheme, shield type
selection, construction organization, operational drainage, maintenance, and
ventilation. As a result, a key technological integration system is developed
for river-crossing tunnels in mountainous cities. The
findings are as follows: (1) The slurry balance shield effectively accommodates
geological conditions of 0.9 MPa high water pressure and sandstone-mudstone interbedding, thereby preventing water and mud inrush and
enhancing tunneling efficiency. (2) In-tunnel shield
assembly and disassembly are implemented using launch and reception tunnels
with diameters of 8.5 m and 4.0 m, respectively, successfully mitigating the
risks associated with conventional ultra-deep shaft
construction and reducing urban disruption. (3) A mushroom-shaped cross-section with an ultra-large area of 613 m2 is adopted, and multi-section stepped excavation with composite support using rib-plate-anchor retaining walls ensures
construction stability. (4) A segmented operational drainage system and an
under-rail corridor ventilation layout are established,
and slurry transport is conducted via shipping, addressing challenges related
to high water pressure, seepage, and environmental protection in urban areas.
Engineering practice confirms that the proposed integrated technology system
effectively reduces construction risks and urban impact while improving the
quality and efficiency of tunnel construction in mountainous city environments.
TAO Weiming
,
CHEN Yang
,
PU Song
,
CAO Linwei
,
LIU Baolin
,
KUANG Wentao
. Scheme Design and Key
Technology of Yangtze River Tunnel of Chongqing-Hunan High-Speed Railway in Chongqing, China[J]. Tunnel Construction, 2025
, 45(6)
: 1219
-1228
.
DOI: 10.3973/j.issn.2096-4498.2025.06.017
