Abstract：
The weathered trough in seabed is a bad geological body with broken rock and poor self-stability. The
left tube of the sea-crossing section of Xiamen second west passage (Haicang tunnel) passes through the longest weathered trough in China, with a total length of 160 m. The construction of subsea tunnel passing through weathered trough is difficult and risky. Once water inrush occurs, it will lead to disastrous consequences. In view of this,key construction technologies for tunnel passing the weathered trough are studied in detail based on engineering background of Haicang Tunnel. Specific schemes and methods, such as comprehensive advance geological prediction system, advance support, advance grouting for water blockage, grouting effect test and construction procedures of CD excavation method, are summarized as well; meanwhile, the tunnel displacement and deformation are densely monitored, measured and analyzed in the process of construction, ensuring the safe construction in weathered trough section.
2021, Vol. 58 