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CRCC 15th Bureau Guangshengang Railway Tunnel Project

Hyperbaric Tunneling

CRCC 15th Bureau Guangshengang Railway Tunnel Project

Intervention at 3.8bar Overpressure

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The Guangzhou-Shenzhen-Hong Kong Express Rail Link is a committed cross boundary transport infrastructure project, which will provide high speed rail services between Guangzhou and Hong Kong, and a connection to the national high-speed passenger rail network serving major mainland cities outside of Guangdong province. This network, which will comprise some 16.000km, is under construction since 2012.

The CRCC, measuring about 2x3.253km length from Shenzhen to the Boundary, will use a dedicated corridor to ensure that the required capacity of trains running at 200 kilometer per hours can be achieved, whilst ensuring operational compatibility with the Mainland of Hong Kong. The tunnel straddles 2 territories with 1.763m in China and 1.490m in Hong Kong.

Compressed Air Work is the major task to carry out. The maximum overpressure was 4.6bar. But this time the job was more extreme. The 4 stators and the flushing nozzle had to be renewed completely from the back side of the cutterhead (Ø9.18m). The total time of this work was more than 4 weeks, day and night. The pressure was up to 3.8 bar overpressure in air.

Maintenance and Repair under compressed air is performed at up to 4.6 bar air pressure for works at the cutterhead. Regular compressed air and oxygen decompression is successfully in use. In total more than 30,000h of compressed air works and more than 5.800 man interventions until 31.01.2015 are performed. No minor cases of decompression illness are reported.