The key facts

  • The spans of the southern Hangzhou Bay bridge have been connected: total length 814.5 m, main span — 364 m.
  • The complex, part of the Nantong–Ningbo line, is designed as the world's longest sea high-speed railway bridge — 29.2 km.
  • Vessels with a deadweight of up to 3,000 tonnes will be able to pass under the bridge; BeiDou and digital monitoring were used.

Key construction stage completed

As Global Times reports, builders have connected the steel spans of the southern bridge, part of the Nantong–Ningbo high-speed railway line. The bridge complex across Hangzhou Bay, stretching 29.2 km, is designed as the world's longest high-speed railway bridge crossing over the sea. The project includes three bridges over the northern, central and southern navigation channels, as well as connecting sections in open water and shallow areas.

Parameters of the southern bridge

The total length of the southern bridge, whose spans have been connected, is 814.5 metres, with a main span of 364 metres. Vessels with a deadweight — the total mass of cargo, fuel and other supplies — of up to 3,000 tonnes will be able to pass beneath it.

Harsh natural conditions

Construction is being carried out in difficult conditions: the water level difference in Hangzhou Bay between high and low tide reaches almost nine metres. Strong currents and winds limit the time available for work at sea. Additional difficulties are created by high humidity, the saline environment and the seabed terrain changing due to erosion and sediment accumulation.

Installation technologies

To connect the spans, a technology of incremental launching of steel structures towards each other from two sides was used. Docking accuracy was ensured by BeiDou satellite navigation and digital monitoring tools. Sensors on the piers, steel structures and temporary holding elements transmitted data on stress in the metal, cable tension and element displacement every few milliseconds. Special limiters and devices helped reduce wind impact and adjust the position of the structures during the work.

Night work and warning system

The joining was deliberately carried out at night: with more stable metal temperature, thermal expansion and contraction interfered less. The builders also created an early warning system for dangerous weather and water conditions; the work schedule was adjusted according to the current situation.

What comes next

Next comes the staged adjustment of cable tension, concreting of the connecting sections, installation and tensioning of the remaining cables, and installation of permanent support elements. After that, the bridge structure will be switched to its permanent operating scheme.