Technologies for large cross-section subsea tunnel construction using drilling and blasting method

This paper reviews the progress made by our research team in the construction of large cross-section subsea tunnels using the drilling and blasting method. Our research on the prevention and control of water inrush during the construction period and the control of water leakage and discharge during the operational period is introduced. It includes a compound grouting technology for high permeable ground, an elaborate process control method for large cross-section tunnels and an active controlling waterproof-drainage system. These achievements were applied to the first two large cross-section subsea tunnels in China, namely the Xiamen Xiang’an Tunnel and the Qingdao Jiaozhou Bay Tunnel. Thereafter, the technical mode of subsea tunnel construction using the drilling and blasting method was established, providing a theoretical basis and systematic technical support for the safe construction of large cross-section subsea tunnels under complex conditions.