In North China’s port city of Tianjin, a massive tunneling machine with an ultra-large diameter — developed by China Railway Group Limited — rolled off the production line on July 2.
The 105-meter-long, earth pressure balance (EPB) shield tunneling machine boasts a diameter of 11.16 meters and is expected to be deployed for the construction of the Metro Line 2 extension project in Riyadh, capital of Saudi Arabia. Most notably, it is China’s first tunneling machine to be exported to Saudi Arabia.
The EPB shield machine with an ultra-large diameter, developed by China Railway Group Limited, rolls off the production line in Tianjin. [Photo/sasac.gov.cn]
The extension section of the Riyadh Metro Line 2 features long stretches of clay-like sand and moderately weathered limestone, which could precipitate wearing and clogging of the tunneling machine’s cutterhead.
To deal with these anticipated issues, Chinese engineers have fitted the tunneling machine with an ultra-high-pressure water sprayer and adopted more protective measures to enhance the equipment’s performance.
The metro extension project spans 8.4 kilometers, with 6 km requiring tunneling work. Once open to traffic, it’s expected to improve Riyadh’s urban transport network, enhance transport capacity and promote the city’s sustainable development.
(Executive editor: Zuo Shihan)
