East section of cross-sea tunnel drilled through in Shantou, China

The east section of Shantou Bay cross-sea tunnel, a 6.68 km-long large-diameter tunnel, has been drilled through in Shantou, China.

The construction faces many difficulties due to complex geological conditions including hard rocks.

The shield tunneling section is over 3 km long.

Constructors have made a breakthrough in the large-diameter shield tunneling.