The Shiziyang Tunnel of Guangzhou-Shenzhen-Hongkong High Speed Rail Link designed by SIYUAN is the first underwater railway tunnel with shield tunneling method in China. The whole line was open to traffic on March 12, 2011.
Guangzhou-Shenzhen-Hongkong High Speed Rail Link is an important part of China’s “four transverse four longitudinal” railway network as well as a large-scale infrastructure project for alleviating the tense transportation between Guangdong and Hongkong, with a full length of about 140km. The Shiziyang Tunnel located at Nansha district of Guangzhou, 10.8km long for each line (left line and right line), crosses three waterways named Xiaohuli, Shazili and Shiziyang respectively. It’s currently the first underwater railway tunnel with the longest mileage and the highest construction standard in China.
Since the tunneling of the first shield machine for Shiziyang Tunnel on November 9, 2007, the construction, design and research departments had been working together to tackle some key world-level technical problems such as cutting tool replacement for shield machine under the geological conditions of “high water pressure and strong permeability”, etc., successfully crossing the deep-water, silty and extremely shallow-buried segments, and realizing the accurate underwater butt joint of shield machines. Under the specially complicated geological conditions with soft and hard interbedded formations, the one-time tunneling length with shield machine achieved more than5km, with the butt joint of shield machines carried out 60m underwater, which is unprecedented in the history of tunnel construction all over the world.
In terms of safety design, the tunnel can satisfy the following “seismic, fire, explosion, and flood resistance” requirements, i.e. anti-seismic design for earthquake of up to grade 7, anti-blast design for explosive of up to 5kg gunpowder, anti-flood design for 300-year flood. Double sealing strip is adopted for waterproof, satisfying the 100-year durability requirement. Besides, the 19 cross escape passageways designed inside the tunnel can used for safety evacuation of people in case of fire disaster or train collision accident, etc.