Trelleborg’s engineered products unit has secured a contract from Penta Ocean and China State JV to seal an immersed tube tunnel for the Shatin to Central link project by MTR Corporation in Hong Kong.
The 1.3km-long tunnel will carry twin rail tracks connecting Kowloon with Hong Kong Island.
Under the contract, Trelleborg’s Gina gaskets will be used to connect 11 concrete elements of approximately 160m each on the Shatin to Central link project.
Supplied as closed rectangular frames, Trelleborg’s Gina gaskets serve as the primary seal to prevent water ingress caused due to external water pressure.
These gaskets are used to seal each sectional element, along with Omega seals, to connect each segment together.
Both Gina gaskets and Omega seals have the ability to withstand seismic activity and absorb movement, the company said.
The combination of the two seals enables the transfer of hydrostatic loads and movements between the tunnel ends which are caused by soil settlement, creep of concrete, temperature effects and earthquakes.
Trelleborg engineered products operation infrastructure sales manager Andre de Graaf said: "Our tunnel seals enable installers to deploy a lighter force jack to seal the deeper joints, as the Gina gasket is softer and able to close more easily upon initial compression. Therefore, these solutions help to reduce costs and the time it takes to close the seals."
The 370mm x 370mm Gina has different rubber hardnesses for optimised sealing performance.
Designed with two cross-weaved reinforcement layers made of nylon, the Omega seal can withstand extreme movements.
The seals can perform at 3.8 bars pressure at a depth of 28 meters, but have the ability to withstand up to 5.0 bars.
Site works on the Victoria Harbour have been initiated and Trelleborg has started production of gaskets for the project.
Phase I and Phase II of the Shatin to Central link project is expected to be completed by 2018 and 2020 respectively.
Image: Trelleborg to supply gaskets to seal the Shatin to Central link tunnel. Photo: courtesy of Trelleborg.