Trelleborg two-seal combo helps keep immersed tube watertight

Main contractor Penta-Ocean China State Joint Venture (PCJV) is using Trelleborg’s Gina gasket which is formulated to prevent water ingress at extreme pressures. It is also using Omega – a seal which serves as a second line of defence and is claimed to endure ‘the most severe ground movements’.

The two-seal combination is designed to allow the transfer of hydrostatic loads and movements between the tunnel ends, caused by soil settlement, concrete creep, temperature effects and earthquakes.

John McLeod, Project Director, at PCJV said: “Trelleborg’s sealing systems proved to be an easy-to-install solution when connecting 1,660m of the tunnel’s concrete panels. With the Gina gasket being of a softer rubber than other sealing systems, it could be closed more easily upon initial compression. This meant that our installers could deploy a lighter jacking force to seal the deeper joints and reduce the time it took to close the seals, which also reduced costs.”

This is the sixth immersed tube in Hong Kong and the first such project for 20 years.
The cross-harbour section of the Sha Tin to Central Link is expected to open in 2022, and will run from Hung Hom station in Kowloon, to Admiralty station on Hong Kong Island.