Hong Kong-Zhuhai-Macao Bridge

Artificial islands, immersed tunnels, marine viaducts and cable-stayed bridges – a bridge with as many engineering records as it covers kilometres.

The innovations involved in the Hong Kong-Zhuhai-Macao Bridge saw it named as the Outstanding Project of the Year in the 2021 FIDIC Projects Awards.

As an exceptional large-scale offshore project, the 55km ‘bridge’, which includes submerged tunnels, comprises the world’s longest sea-crossing channel and two artificial islands with a length of 625m and an area of around 100,000m2.

The unique 5.7km long immersed tunnel is buried 40m below the sea level, for the convenience of a planned shipping channel reserved for 300,000 DWTtankers. The design of three cable-stayed bridges also provide an elegant and unique landscape for the Greater Bay area.

Innovation is key
A project of this scale has only been possible thanks to innovative approaches design and construction. Standardised components were manufactured onshore, while large-scale equipment was created to assemble the bridge on site. This allowed for a dramatic reduction in offshore construction, which in turn allowed for a much safer delivery.

The Total Recordable Incident Rate for this vast project was below 0.2, and the Lost Workday Case Rate was even lower at 0.15. That is a remarkable safety record for a project that includes a record-breaking immersed tunnel weighing 80,000tons, which was installed within 5cm accuracy in water depth of 40m.

Dolphins
All of this took place in seas that serve as a habitat for the endangered Chinese white dolphins.

This made onshore manufacture a valuable environmental advantage. At the same time, implementing new technologies like deep inserting large cylinders and compacting sand piles meant underwater dredging was reduced by around 10 million m3.

Real time environmental monitoring and supervision with a stop work authority in place for any incident, further protected native species and by the end of construction, Chinese white dolphin numbers had risen to more 2300, up from an estimated 1500 before the project began.