In a significant engineering feat, the tunnel boring for the Qingdao Jiaozhou Bay Second Underwater Road Tunnel has been fully completed. On October 2nd, at a depth of 105 meters below the sea level of Jiaozhou Bay, the “Guohao” tunnel boring machine reached its final section, installing the last precast segment to mark the end of the tunnel’s shield excavation.
A Record-Breaking Undertaking
This project stands as the world’s largest in scale, longest in length, and most complex in construction difficulty for an underwater road tunnel. For context, the first Jiaozhou Bay Tunnel opened in 2011 and spans 7.8 kilometers.
Project Scope and Progress
The Qingdao Jiaozhou Bay Second Underwater Road Tunnel boasts an impressive total length of 17.48 kilometers. The recently completed shield-driven section measures 3,255 meters, while the service tunnel extends for 5,854.6 meters. The main tunnel is designed with a “dual main tunnel + service tunnel” layout. Reflecting the geological conditions of Jiaozhou Bay, the construction employed a hybrid approach, combining drill-and-blast methods with tunnel boring machines.
Currently, the drill-and-blast section is over 90% complete. The project team anticipates that the service tunnel will be the first to achieve full connection by the end of this year or early next year.
Connecting Qingdao’s Future
Upon its completion, the Jiaozhou Bay Second Underwater Road Tunnel will serve as a vital link between Qingdao’s Shibei District and the West Coast New Area. This new artery, alongside the existing Jiaozhou Bay Tunnel, the Jiaozhou Bay Cross-Sea Bridge, and the Ring Expressway, will establish a multi-layered and comprehensive cross-bay transportation network. This development is set to propel Qingdao into a new era of connectivity, often referred to as the “Dual Tunnel Era.”
The successful completion of the tunnel boring marks a critical milestone in this ambitious infrastructure project, paving the way for enhanced regional integration and economic development in Qingdao.
