China’s Danyang-Kunshan Grand Bridge is World’s Longest

Every country in the world is diligently engaged in efforts to outdo each other in development. Roads and railways play a fundamental role in the infrastructure of any country and we have mentioned several such achievements in our previous videos.

You must have traveled many times by rail and road and crossed a few bridges whose length would have delighted and amazed you.

Imagine a bridge that doesn’t take you a few seconds or minutes to cross, but feels as if the seemingly endless distance on that bridge takes you to another world.

But now such a bridge has become a reality from the world of imagination. Many people in eastern China have become accustomed to traveling on a bridge that crosses several fields, barns, rivers and lakes at the same time, which might have been beyond their imagination about 15 years ago.

It is the world’s longest Danyang–Kunshan Grand Bridge built over the Yangtze River Delta, which was constructed in a record time of 4 years at a cost of $8.5 billion.

The bridge currently holds the Guinness World Record for longest bridge in the world since June 2011.

This 164.8 km long modern-day engineering marvel is a part of Beijing-Shanghai high speed railway, which has revolutionized the concept of bridge construction.

The bridge was built by Road and Bridge Corporation, a subsidiary of China Communications and Construction Company, and the mega structure was meant to ease railway traffic in the area.

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Before the construction of the Danyang-Kunshan Grand Bridge, the travel time in the Eastern coastal area of China, especially between major cities like Nanjing and Shanghai was a long and tiring task. Travel time from Ningbo to Jiaxing by public transport was 4.5 hours, which has now been reduced to just 2 hours.

The Danyang-Kunshan Grand Bridge consists of two main sections, namely the Danyang Section, which is 52.4 km long, and the Kunshan Section, which is 112.4 km long. The clearance of this bridge is 150 meters, under which even ships can pass easily.

The construction of the world’s longest bridges also often creates controversy, between those who believe that the earth is flat and those who believe that the earth is round according to the principles of science.

For people who believe the earth is round, it is extremely important to take the curvature of the earth into account in the design and construction of long roads and bridges anywhere in the world.

According the principles of engineering the constructing any road over 100 km straight is a difficult task and that is why the Danyang-Kunshan Grand Bridge has curves added to it, adding to its beauty. The bridge continuously crosses over a 150 river channels wider than 20 meters, rice paddies, lakes and rugged terrains besides various important towns and cities.

The region where the Danyang-Kunshan Grand Bridge is located is so full of waterways that many small bridges were needed to build the railway line here, which would have been expensive and time-consuming.

In addition, the construction of a railway above ground in this fertile region was likely to not only destroy many farms, but also displace various communities and disrupt their lives and livelihoods.

In such a situation, there was a need for a high-speed railway to pass through these areas without making any major changes here. This idea led planners to the Danyang-Kunshan Grand Bridge, which would be built on pillars 100 feet above the ground.

This mega project has used enough steel to build 60 Eiffel Towers. This feature has not only given it the ability to withstand severe earthquakes, but this powerful bridge does not sway even when it withstands strong typhoons and a direct hit from naval ships which can weigh up to 300,000 tons. Its section spanning Yangchang Lake is constructed of 200 pillers, while the remaining 9,500 concrete pilings use 450,000 tons of steel.

During the meticulous planning and execution of the structure and installation of the pillars in the lake, special consideration has been given to the aquatic life and ecosystem.

The bridge was built along the Beijing-Shanghai high-speed railway in Shanghai and Nanjing, two major cities in Jiangsu Province, allowing the nearly 1200 km distance between Beijing and Shanghai to be crossed in less than 5 hours.

This feat of engineering has significantly helped in solving the railway problems in the region, facilitating daily commuting of the people, business travel and access to various neighboring cities.

Construction activities on the Danyan-Kunshang Grand Bridge project began on April 18, 2006, with more than 10,000 workers participating. A masterpiece of engineering prowess, this unique project was completed in June 2011 in a record time of 4 years.

The world’s longest viaduct bridge cost $51 million per kilometer while the total cost was $8.5 billion. Connecting various cities and regions along the way, the bridge has also successfully overcome the challenges of rapid access to the small agricultural areas of the Yangtze River Delta.

This bridge is an example in the world of construction, bearing the weight of heavy traffic and high-speed railway. To withstand the intensity of a severe earthquake, the bridge has been assisted by advanced engineering, whereby base isolators, elastomeric bearings and sliding plates have been installed in its foundations.

Expansion joints are added to the rail track to withstand ground shaking and movement during earthquake shocks.

Special arrangements have been made in this project to withstand the severity of the weather, so that during the typhoon, not only the structure will be protected from any kind of damage, but with stainless steel and protective coatings, it will also be highly resistant to corrosion and rust. The principles of aerodynamics have been carefully considered in the design of its anchorage system to withstand the force of wind during a typhoon.

The construction of the Danyang-Kunshan Grand Bridge has highlighted various aspects of engineering expertise, particularly the robust construction of different terrains, connectivity to cities, and swampy areas.

The bridge has been designed using a combination of cable-stayed and beam bridge design to cross different widths of rivers and canals, while the use of prefabricated segments in the elevated section has enabled minimal disruption in the urban areas.

The bridge also features a long-term maintenance plan, which includes regular inspections of various sections of the bridge and special coatings to protect against corrosion. Meanwhile, the layers of protective materials on the metal components are examined and those prone to rust or corrosion are replaced in time.

The design and construction of the Danyang-Kunshan Grand Bridge actually took the curvature of the earth into account, and significant changes were made to the design in view of this curvature during the survey for the project.

During the advanced techniques of the survey, great attention was paid to ensure the alignment and integrity of the bridge in terms of the curvature of the earth. Calculation of the Earth’s radius and geodetic measurements ensured that all the principles of geological science were closely examined in each segment of the bridge.

Danyang-Kunshan Grand Bridge is not only a means of connecting different areas and a passage for transportation, but also plays an important role in the development of southern Jiangsu. This area may account for 0.3% of China’s total land area and 1.7% of its total population, but it accounts for 17% of China’s imports and exports.

This amazing bridge has the potential to attract both local and foreign tourists, whose length, structure, design and strength are now the talk of the town.

China has been surprising the world for the past few decades with its research, unique mega projects and innovation. Maybe while you are reading this article, preparations to set a new world record in some part of China are in full swing.

The list of China’s unique mega projects is getting longer and longer, so we would love to know if you let us and other subscribers of this channel know about your favorite project among them.