language
Higher water pressure
Our products have been widely used in urban subways, railway and highway tunnels, cross-sea and cross-river tunnels, municipal utility tunnels, hydraulic engineering projects, and other fields.
Our customers are located in major cities across China and also export to global markets including the Americas, Europe, Southeast Asia, and the Middle East. We have established strong partnerships with numerous large construction groups and tunnel-boring machine manufacturers.
It is the world’s first large-diameter shield tunnel located in an area with an earthquake intensity of 8 degrees. It is also Guangdong Province’s first highway tunnel constructed using the shield method beneath the sea, and has been dubbed “the most challenging large-diameter shield project” in China. At its deepest point, the tunnel lies 98.5 meters below sea level, situated in a region experiencing high seismic intensity of magnitude 8. To overcome challenges such as nearly 100-meter-high water pressure and severe chloride corrosion, the tunneling machine had to bore through extremely hard granite strata with a compressive strength of up to 200 megapascals. The shield tunnel section successfully passed through a 135-meter-long fault zone thanks to advanced ground consolidation measures applied ahead of the tunnel face. During construction, the team set several remarkable records: 14 meters per shift, 24 meters per day, and 432 meters per month—breaking the previous record for domestically produced ultra-large-diameter slurry balance shield machines.
Shenjiang Railway Zhujiang Estuary Tunnel
The hydrogeological challenges are of world-class magnitude. The tunnel has to pass through 13 different geological strata and 17 fault zones, with a solid rock section spanning an impressive 2.75 kilometers. The granite exhibits a compressive strength as high as 124.6 megapascals, and 22% of the tunnel’s length consists of alternating soft and hard strata. Meanwhile, the maximum water pressure reaches 1.06 megapascals—equivalent to 10.6 kilograms of pressure exerted on the tip of a fingernail. The tunnel’s maximum underwater burial depth is 115 meters, setting a new record for the deepest undersea railway tunnel in China. The tunnel’s geological conditions are exceptionally complex, with highly variable and intricate rock types, posing enormous challenges to both equipment performance and construction techniques. It presents three globally challenging issues: long tunnel lengths, ultra-high water pressures, and extremely complex geology.
Foguan Intercity New Shiziyang Tunnel
This tunnel was once the world’s largest-diameter underwater railway tunnel. It features a single-bore, double-track design, with a shield tunneling machine advancing alone for a total distance of 4.9 kilometers. During construction, the project encountered maximum water pressures as high as 0.9 megapascals and had to pass through three fractured zones and three sections of high-strength, full-face hard rock. Sections of full-face hard rock accounted for 48.5% of the tunnel’s total length, with the rock exhibiting a maximum saturated compressive strength of up to 75.7 megapascals. In response to this complex and varied geological environment, the construction team developed an efficient construction methodology, achieving a record-breaking monthly advance rate of 304 meters. The construction progress in the composite geological formations reached as much as 180 meters per month, with an average progress rate of approximately 126 meters per month—far exceeding typical tunneling speeds under similar complex conditions. This tunnel has truly become a high-standard, high-risk underwater railway tunnel for intercity rail transit.
