Abstract Based on the engineering design practice of the Xiangyang Hanjiang Immersed Tube Tunnel, and in view of the tunnel characteristics, such as strong scouring, deep and thick highly-permeable ground and high requirement for flood control, this paper investigates the various aspects in terms of the tunnel design, including the horizontal-and longitudinal layout of the tunnel, the tunnel element structure and water-stopping structure of the joints, the type and structure of the dry dock, foundation and backfilling of the immersed tube tunnel, final closure joint structure and water-stopping structure of the connection ends. The results show that: (1) for the inland river immersed tube tunnel, the arrangement scheme of long-distance dual-axis dry dock is adopted, and the support and water isolation problems of the deep foundation in highly permeable strata are solved through a combination of technologies,such as lattice underground diaphragm wall, ultra-deep closed curtain, underground diaphragm wall with prestressed anchor cables and concrete sealing bottom; (2) the full-face continuous casting technology is used to prefabricate monolithic elements, and the independently developed water stop profiles are first used for the element joints;(3) for the inland river immersed tube tunnel, a high-precision floating leveling barge is used for pre-paving the peb? ble foundation, and the anti-scouring solution is provided for the top of the elements in strong scouring areas; (4) the land final joint without independent thrust structure is used, and at the connection end the support structure composed of large diameter interlocked steel pipe piles and outside water-stopping wall as well as the secondary waterstopping structure composed of piece-by piece hoisted double-wall steel cofferdam are installed according the project demand.
Abstract：
Based on the engineering design practice of the Xiangyang Hanjiang Immersed Tube Tunnel, and in view of the tunnel characteristics, such as strong scouring, deep and thick highly-permeable ground and high requirement for flood control, this paper investigates the various aspects in terms of the tunnel design, including the horizontal-and longitudinal layout of the tunnel, the tunnel element structure and water-stopping structure of the joints, the type and structure of the dry dock, foundation and backfilling of the immersed tube tunnel, final closure joint structure and water-stopping structure of the connection ends. The results show that: (1) for the inland river immersed tube tunnel, the arrangement scheme of long-distance dual-axis dry dock is adopted, and the support and water isolation problems of the deep foundation in highly permeable strata are solved through a combination of technologies,such as lattice underground diaphragm wall, ultra-deep closed curtain, underground diaphragm wall with prestressed anchor cables and concrete sealing bottom; (2) the full-face continuous casting technology is used to prefabricate monolithic elements, and the independently developed water stop profiles are first used for the element joints;(3) for the inland river immersed tube tunnel, a high-precision floating leveling barge is used for pre-paving the peb? ble foundation, and the anti-scouring solution is provided for the top of the elements in strong scouring areas; (4) the land final joint without independent thrust structure is used, and at the connection end the support structure composed of large diameter interlocked steel pipe piles and outside water-stopping wall as well as the secondary waterstopping structure composed of piece-by piece hoisted double-wall steel cofferdam are installed according the project demand.
WANG Yong XU Guoping LI Yong LIU Minghu REN Yaopu XU Yu FAN Zhe
.Key Technologies in the Design of the Xiangyang Hanjiang Immersed Tube Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(2): 192-199
2022, Vol. 59 