Trelleborg supplies widest immersed tunnel

The link, which connects Shenzhen and Zhongshan, is 24km in length and consists of two artificial islands, two bridges and a two-way, eight-lane tunnel that has a width of up to 46m. This will make it the world’s largest and widest immersed tunnel upon completion in 2024.

Richard Hepworth, president at Trelleborg’s marine and infrastructure operation, said: “We are delighted to have been awarded the contract for the ShenZhong Link, yet another high profile infrastructure project, central to China’s 13th Five-Year Plan (2016-2020), and look forward to yet again working closely with CCCC Fourth Harbour Engineering Co., Ltd.”

Preventing water ingress

Trelleborg will supply its Gina gaskets and Omega seals, which are to be used between the sectional elements of ShenZhong Link’s immersed tunnel to prevent water ingress due to external water pressure.

The Gina gasket consists of different unique ingredients for optimised sealing performance. The Omega seal serves as the secondary, safety seal that can withstand extreme movements. It is designed with two cross-weaved reinforcement layers made of nylon for durability and strength. The combination of the two seals enables the transfer of hydrostatic loads and movements between the tunnel ends, caused by soil settlement, creep of concrete, temperature effects and earthquakes.

By Rebecca Jeffrey