The authors focus on tunnel construction in three
extreme environments: difficult mountainous areas, deep water areas, and
sensitive urban areas. In particular, they meticulously organize and outline
the primary challenges, relevant technological advancements, and future
developmental trends associated with tunnel construction in these environments.
Regarding extreme conditions such as high stresses, high temperatures, high
altitudes, and active fault zones in difficult mountainous areas, the authors
discuss the deformation mechanism, failure modes, and protective strategies of
surrounding rocks and tunnels. It suggests that in the future, more accurate
prediction models can be established using big data, machine learning, and
other methodologies to enable realtime monitoring and risk
assessment of tunnel construction processes. Further, regarding extreme
conditions such as high water pressures, intense earthquakes, and high erosion
rates in deep water areas, the authors delineate the deterioration and failure
mechanisms of tunnel segments and joints employing the immersed tube and shield
tunneling methods under multifactor coupling. Additionally, the authors
summarize key technical strategies to improve the mechanical robustness and
durability of these structures while advocating further research on the
waterproofing, seismic, and erosion resistance of submarine tunnel segment
joints, thus establishing a comprehensive theoretical and technical system.
Finally, regarding the complexities of tunneling through existing tunnels,
sensitive structures, and underground obstacles in sensitive urban areas, the
authors summarize environmental response laws, relevant geological deformation
assessment methods, and technical control strategies associated with shield
tunneling and pipe jacking methods. They propose that in the future, machine
learning and alternative technologies can assist in tunnel construction,
improve prediction accuracy and control, and minimize disturbances to the urban
environment throughout the construction process. Overall, although pertinent
research results offer crucial support for tunnel construction in extreme
environments, certain technologies need further improvement and standardization
in their practical applications to guide subsequent engineering construction.
With the development of nextgeneration information
technology, future tunnel construction will inevitably move toward
digitization, intelligence, and automation, ensuring the safety, sustainability,
and efficiency of tunnel construction in extreme environments.