The Changtai Yangtze River Bridge is one of China’s key national infrastructure projects under the 13th Five-Year Plan and represents a landmark river-crossing development. The bridge features a giant steel-concrete caisson weighing more than 220,000 tons, making it one of the world’s largest and most challenging caisson foundation construction projects.
To support the underwater excavation and sinking operations of this massive structure, VVLAI developed a comprehensive intelligent dredging solution based on its SJT850 Hydraulic Dual-Cutter Suction Dredger, complemented by self-developed Crawler-Type and Gantry-Type Intelligent Cutter Suction Robots. These technologies provided critical support for the safe, stable, and balanced sinking of the giant caisson.
The deepwater environment inside the caisson created significant visibility limitations, making it difficult to accurately assess excavation progress and monitor underwater operations using conventional construction methods.
Key structural areas such as:
-Caisson cutting edges
-Internal partition walls
-Shear keys
-Narrow confined spaces
were difficult or impossible to access using traditional excavation equipment. Incomplete soil removal could result in uneven loading, differential settlement, and instability during the sinking process.
Sections of the Yangtze River seabed contained dense and compact soil layers. Conventional dredging equipment often struggled to achieve both high excavation efficiency and the precise soil removal required to maintain balanced caisson sinking.
The project contributed to the construction of one of the world’s largest bridge caisson foundations, providing advanced underwater excavation technology for a landmark infrastructure development.
VVLAI’s intelligent dredging robots successfully accessed and excavated areas unreachable by traditional equipment, achieving comprehensive soil removal throughout the caisson structure.
The project introduced intelligent digital control technologies that enabled real-time visualization and precise management of underwater excavation operations.
VVLAI deployed the SJT850 Hydraulic Dual-Cutter Suction Dredger together with its independently developed Crawler-Type Intelligent Cutter Suction Robot and Gantry-Type Intelligent Cutter Suction Robot, creating a complete underwater excavation and sediment removal solution.
Through an advanced digital control platform, the entire underwater excavation process became visible and manageable in real time. Intelligent navigation and automated excavation guidance improved operational precision and ensured stable construction progress.
The intelligent robots were equipped with multi-axis robotic arms capable of:
-360° rotation
-Flexible extension and retraction
-Precision positioning
-Access to confined spaces
This allowed excavation inside traditionally inaccessible areas such as cutting edges, partition walls, and shear key sections, ensuring complete soil removal without blind spots.
The excavation system adopted an innovative “Cut-and-Discharge” methodology.
The cutter heads were equipped with high-pressure water jets capable of breaking up compact soil formations efficiently. Combined with high-capacity slurry pumps, excavated materials were immediately transported out of the caisson, significantly improving excavation efficiency while maintaining precise control over soil removal volumes.
The project successfully addressed one of the most difficult challenges in giant caisson construction: achieving precise underwater excavation while maintaining balanced and controlled caisson sinking.
By enabling accurate excavation and comprehensive coverage of critical structural areas, VVLAI’s solution reduced the risks associated with uneven settlement and sinking imbalance.
The successful deployment of VVLAI’s intelligent cutter suction robots expanded the capabilities of China’s domestically developed deepwater construction equipment and contributed valuable engineering experience for future large-scale bridge and offshore foundation projects.
The combination of intelligent robotics, digital visualization, and innovative excavation techniques created a new benchmark for underwater caisson construction and deepwater infrastructure engineering.
The Changtai Yangtze River Bridge Caisson Dredging Project demonstrates VVLAI’s ability to deliver advanced robotic solutions for some of the world’s most challenging underwater construction environments.
Through the successful deployment of the SJT850 Hydraulic Dual-Cutter Suction Dredger and intelligent cutter suction robots, VVLAI enabled safe, efficient, and highly precise excavation operations for a 220,000-ton giant caisson foundation. The project not only contributed to the successful construction of a landmark bridge but also strengthened the technological foundation for future deepwater engineering projects worldwide.
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