China's new mega-project: Shanghai Yangshan deep-water port 上海洋山深水港 part 5/5

Summary

The Dong Hai Bridge, spanning 32 km across the ocean, is a triumph of engineering, overcoming challenges like rough seas, unstable seabeds, and extreme weather conditions. Built to support six lanes of truck traffic and allow ships to pass, its construction required innovative solutions, such as pre-building massive spans on land and transporting them by barge. The bridge not only supports one of the world’s busiest ports in Shanghai but also contributes to the city’s rise as a global shipping hub. Despite ongoing challenges like typhoons, the bridge remains a symbol of resilience and visionary planning.

Takeaways

• 😀 The Dong Hai Bridge is a monumental engineering feat, spanning 32 km, making it the second-longest ocean-spanning bridge in the world.
• 😀 The construction of the bridge was incredibly challenging, requiring a combination of engineering ingenuity and a detailed understanding of nature's forces, such as typhoons and strong ocean currents.
• 😀 The bridge was designed to handle six lanes of truck traffic, withstand typhoons, and accommodate large ships sailing underneath it.
• 😀 The seabed on which the bridge was constructed varied in depth and was made of soft, unstable mud, which made it a difficult foundation to work with.
• 😀 Engineers tested the bridge's design under extreme conditions, simulating truck accidents, waves, and collisions to ensure its durability.
• 😀 The bridge's design includes both box girder and cable-stayed suspension components, with the latter allowing ships to pass underneath.
• 😀 Over 6,000 foundation piles were driven into the sea floor, with precise GPS technology used to position them accurately to within 3 to 5 mm.
• 😀 To avoid construction difficulties at sea, the bridge's massive concrete spans were pre-built on land and then towed out to sea for assembly.
• 😀 The bridge's construction process was a logistical challenge, involving the creation of specialized barges to move and position the heavy concrete spans.
• 😀 Since its opening in 2005, the Dong Hai Bridge has handled nearly 3 million containers, solidifying its role in China's shipping infrastructure.
• 😀 The Dong Hai Bridge is part of Shanghai's broader vision to become the world's largest container port, expected to be completed by 2020 with a 20 km stretch of port capable of handling 25 million containers annually.

Q & A

What is the Donghai Bridge and why is it significant?

The Donghai Bridge is the second longest ocean-spanning bridge in the world, stretching 32 km and six lanes wide. It is significant because it connects the mainland to Yangshan Island, providing access to one of the largest container ports in the world. Its construction was a major engineering challenge due to the harsh conditions of the ocean and its massive scale.

What were the primary engineering challenges faced during the construction of the Donghai Bridge?

The main challenges included the need for the bridge to withstand typhoons, strong ocean currents, and waves of up to 6 meters. Additionally, the unstable seabed, consisting of soft mud, made foundation work difficult, and construction had to be done in rough seas, limiting the time available for building.

How was the foundation of the Donghai Bridge built in such a challenging environment?

Engineers had to drive over 6,000 foundation piles into the seabed using GPS for precise positioning. These piles extended 20+ meters underwater and another 40 meters down to reach stable bedrock, ensuring the structure's stability against the forces of nature.

What was the solution to building the massive concrete spans of the Donghai Bridge?

Instead of constructing the bridge piece by piece at sea, which would have been too difficult, the builders pre-built the massive concrete spans on land. They then towed these spans out to sea using a specially designed barge with a 1,600-ton lifting capacity.

How did the workers manage to live and work in the middle of the sea during construction?

As construction moved further out to sea, the massive bridge pilings were used as dormitories for the workers. This innovative solution allowed them to live and work in the remote, challenging environment while staying close to the construction site.

When did the Donghai Bridge open, and how much traffic does it handle today?

The Donghai Bridge opened to traffic on December 10, 2005, 42 months after construction began. Since its opening, nearly 3 million containers have crossed the bridge, which serves as a critical link to the Yangshan deep-water port.

How does the Donghai Bridge manage to handle the heavy traffic and harsh weather conditions?

The Donghai Bridge is equipped with an advanced control room that monitors traffic and weather conditions through 80 surveillance cameras. These cameras track the bridge's 32 km span, ensuring that any potential issues are detected and addressed immediately, especially during hazardous conditions like typhoons.

What impact did the Donghai Bridge have on Shanghai's shipping industry?

The Donghai Bridge played a key role in moving Shanghai's Yangshan Island from being the third largest container port in the world to the second largest, just 1 million containers behind Singapore. It significantly improved the accessibility and capacity of Shanghai's port infrastructure.

What are the future plans for Yangshan Island's port facilities?

By 2020, the Yangshan deep-water port is set to become the world's largest container port, covering an impressive 20 km and handling 25 million shipping containers annually. This expansion is part of Shanghai's ongoing vision to dominate global shipping logistics.

How has the rapid development of Shanghai's port system impacted its global status?

Shanghai's port system has rapidly developed into one of the largest and most efficient in the world. This transformation has enhanced China's position in global trade, with the city leadership and the public taking immense pride in its achievement, making it a point of national significance.