To further improve the waterproof capability of
underwater tunnels with superdeep water and various geological
conditions, comparison is made between immersed and shield tunnels based on
existing structures and construction technologies. A new type of watershield machine and relevant tunneling technology (guidedshield tunneling) are proposed based on basic technical element
extraction and innovation methods. For the guidedshieldtunneling method, guided tubes are laid in advance as waterproof
structures. Subsequently, the water shield tunnels in the tubes to drain, thus
creating a dry environment to conduct segment erection. Finally, pressurized
grouting is employed to fill the gaps, thus integrating the guided tubes and
tunnel segments to form the main tunnel structures. This method has many
advantages, including low requirements on ground conditions, adaptability to
various waterhead pressures, and good waterproof performance. Thus, this method
improves assembly construction rate and the standardization level of
components, making it a potential mainstream technique in underwater tunneling.
The comparative results of economic indexes show that: (1) the cost of
waterproof structures requires a greater portion of the total cost of the
guidedshieldtunneling method
than that in the shield or immersed tunneling method; (2) the cost of soil
excavation in the guidedshield tunneling method is
much less than that in the shield method; (3) the cost of concrete and main
structures in the guidedshield tunneling method is
much less than that in the immersed tunneling method; thus, the guidedshield tunneling method has good economic benefits.
LI Zengjun
. GuidedShield Tunneling Method: An
Innovative Thought on Underwater Tunneling Method[J]. Tunnel Construction, 2021
, 41(10)
: 1801
-1808
.
DOI: 10.3973/j.issn.2096-4498.2021.10.020
