On the morning of May 20, the shield-tunnel section of the Airport Tunnel of the Longyan Railway urbanized renovation project—Shandong Province's first railway construction project to adopt shield tunneling—reached a key milestone. As the cutterhead slowly rotated and the shield machine advanced gradually, the "Longyan Shiyu No." shield machine successfully completed its launch in the Airport Tunnel shield section undertaken by Shandong Luqiao Group, marking that the Airport Tunnel, the project's last key control works, has officially entered the shield excavation construction stage and pressing the "accelerator" for the breakthrough of the full-line track-laying and girder-erection corridor.

The Longyan Railway urbanized renovation project is jointly invested by Shandong Railway Investment Group and Yantai City, and constructed and managed by the Ji-Qing High-Speed Railway Company. The shield section of the Airport Tunnel is located within Yantai Penglai International Airport, where the surrounding environment is complex and sensitive. The tunnel passes beneath airport building clusters including flood-discharge channels, aviation fuel pipelines, and special vehicle refueling depots, and passes alongside building pile foundations at extremely close distances. The engineering geological conditions are complex and variable: the strata traversed by the tunnel change abruptly from weakly weathered granite to backfill, and the tunnel is overlain by an ultra-thick layer of recent backfill and thick sand layers of the river channel, making open-cut or traditional drill-and-blast mining methods unsuitable. After comprehensive consideration, the shield tunneling method was selected for the design and construction of this tunnel.

Source: Phoenix Net Shandong