When it comes to grandiose engineering structures, the imagination immediately draws giant structures, thrown over wide water barriers or deep gorges. However, the term βlongest bridgeβ is often misunderstood, as there are different categories: bridges over water, viaducts and complex systems connecting the islands. The absolute leader in the overall length is Danyan-Kunshan viaduct China, whose length is striking even to experienced engineers.
This giant facility is part of the Beijing-Shanghai high-speed rail line. It took only a few years to build, which in itself was a technological marvel. It is important to understand that viaduct Often classified separately from classical bridges, but in official record-holders' registers they occupy a leading position due to their continuous construction.
If we talk about bridges, thrown exclusively over the water surface, then here the palm of primacy holds the Bridge over Jinjiao StraitIt is also located in China. These structures demonstrate how modern technologies allow us to travel kilometers of space, linking remote regions into a single transport network.
Absolute record holder: Danyang-Kunshan viaduct
Located in Jiangsu Province, this colossal object stretches over the 164.8 kilometers. This length was necessary to pave the path through rice fields, canals and small lakes, minimizing fertile land. The design is a series of concrete spans, mounted on thousands of supports, extending into the distance to the horizon.
Construction was carried out from 2008 to 2010, and the project involved more than 10,000 workers and engineers. The main material became pre-stressed concreteIt provides the necessary strength and durability with minimal maintenance costs. The construction speed was on average several kilometers per month, which is a phenomenal indicator for objects of this scale.
The viaduct is used exclusively for the movement of high-speed trains, reaching speeds of up to 350 km / h. Passengers following the route Beijing-Shanghai, do not even notice the moment when the train enters the bridge, so smoothly and imperceptibly arranged the route.
β οΈ Attention: Danyang-Kunshan viaduct is designed with the seismic activity of the region in mind. Special dampers extinguish the earth's vibrations, protecting the structure from destruction in earthquakes up to 8 points.
When planning a high-speed train trip in China, book your tickets in advance, as seats on trains passing through Danyang-Kunshan viaduct are sold out a few days before departure.
The largest bridges across the water surface
If you exclude viaducts and consider only structures thrown over water, the list of leaders changes. It's the first place. Bridge over Jinjiao Strait (Qingdao), the length of which is 42.6 km. It connects Qingdao city with Huangdao district, reducing travel time from an hour and a half to 20 minutes.
The second place in this category has long been occupied by the bridge over Lake Pontchartrain in the United States, but it is significantly inferior to Chinese counterparts. Modern projects involve not just connecting the coasts, but creating entire transport arteries that can withstand typhoons and storm surges.
Engineering solutions applied in the construction of the bridge across the Jinjiao Strait include the use of special concretes resistant to salt water. The supports are buried in the seabed for tens of meters, which guarantees the stability of the structure even in severe excitement.
- π Bridge over Jinjiao Strait - 42.6 km (China).
- π Bridge over Lake Pontchartrain 38.4 km (USA).
- π Mansan Bridge - 36 km (China).
The length of bridges across the water often depends on the geography of the coastline. The more the entrance to the reservoir, the longer the dam part of the bridge should be. That is why many record holders are in the deltas of large rivers or in shallow sea bays.
European and American Giants
Although Asia dominates the list of the longest bridges, Europe and America also have outstanding structures. For example, Crimean bridge (formerly Kerch), connecting the Kerch Strait, has a length of about 19 km. This is a complex engineering structure that takes into account the ice load and seismic risks of the region.
The U.S. Bridge is known Lake Pontchartrain CausewayIt has long been considered the longest in the world. It consists of two parallel structures, one of which was built in the 1950s. Despite its age, it remains an important Louisiana transport artery.
European bridges are often inferior in length due to dense construction and the lack of such extensive shallow waters as in China. But they compensate for this with the complexity of the architecture and the historical value. Many of them are not just roads, but tourist sites.
β οΈ Note: When visiting long bridges in coastal areas, consider the tidal schedule, as well as possible speed limits in strong side winds.
Technical features of long spans
Creating a bridge tens of kilometers long requires solving many unique tasks. The main one is thermal expansion. Concrete and steel change their sizes depending on temperature, and at a length of 100 km, these changes can be several meters. Special temperature stitches are used to compensate.
Another important aspect is aerodynamic stability. Long spans over water are subject to strong winds. Engineers use streamlined beam shapes and windscreens to prevent resonance oscillations that could lead to destruction.
Example of strain calculation:
ΞL = Ξ± L ΞT
Where:
ΞL is the change in length
Ξ± is the linear expansion coefficient
L is the reference length
ΞT is the change in temperature
Lighting such giants is also a separate engineering task. Thousands of supports and a kilometer-long canvas should be visible at night, but the light should not blind the pilots of ships or interfere with the ecology of the region.
How do bridges protect against corrosion?
To protect against rust, a multilayer system is used: galvanizing, epoxy primers and finishing polyurethane coatings. In an aggressive marine environment, cathode protection is additionally applied, applying an electric current to metal parts, which prevents oxidation.
Comparative table of record holders
For clarity, compare the main parameters of the most famous long bridges in the world. The data may vary slightly depending on the measurement method (only the main part or together with the access roads).
| Name of the bridge | Country. | Length (km) | Type | Opening year |
|---|---|---|---|---|
| Danyan-Kunshan viaduct | China | 164,8 | Railway | 2011 |
| Bridge over Jinjiao Strait | China | 42,6 | Automotive | 2011 |
| Bridge over Lake Pontchartrain | USA | 38,4 | Automotive | 1969 |
| Mansan Bridge | China | 36,0 | Automotive | 2007 |
| Hengzhou-Bei Bridge | China | 35,7 | Automotive | 2008 |
As you can see from the table, China is the dominant position on the list. This is due to the extensive development of infrastructure and the availability of suitable geographical conditions in the eastern provinces of the country.
Environmental and economic aspects
The construction of super long bridges is always a matter of debate among environmentalists. Laying a path through water bodies can disrupt the migration routes of fish and birds. Therefore, modern projects must include environmental assessment. Animal walkways or artificial reefs are often built to compensate for damage.
From an economic point of view, such bridges pay off for decades. They reduce logistics costs, integrate labor markets and stimulate tourism. For example, the Jinjiao Strait Bridge created a single economic zone around Qingdao.
βοΈ Factors of success of the long bridge
The cost of servicing such giants is also enormous. Annual inspections, road repairs and replacements of lighting elements require constant investment. However, the profit from toll travel (where it is) often outweighs these costs.
The future of bridge building
Engineers are already planning projects that will surpass current records. The options of bridges across the Bering Strait or connecting the islands of Indonesia are being considered. New materials such as carbon-fibre And super-strong concrete, make the spans even longer and easier.
Automation of construction will also take a new level. Robotic systems will be able to collect spans faster and safer for humans. In 20 years, the question of where is the longest bridge will have a different answer.
β οΈ Attention: The design of future bridges takes into account not only current traffic, but also the projected growth in the number of electric vehicles requiring charging infrastructure right on spans.
The length of the bridge is not just a record, it is the result of a complex balance between economic feasibility, engineering capabilities and environmental safety.
FAQ: Frequently Asked Questions
Why are the longest bridges in China?
This is due to the countryβs rapid economic growth, the need to link remote regions and the availability of huge resources for construction. In addition, the geography of eastern China with its river deltas is ideal for creating long viaducts.
How long does it take to travel on the longest bridge?
On a high-speed train moving at a speed of 300-350 km / h, the journey on the Danyang-Kunshan viaduct takes about 25-30 minutes. On a car on conventional bridges of this length, the journey time is from 20 to 40 minutes, depending on the flow speed.
Is there a fee for travel on these bridges?
Most of the major bridges in China and the United States are toll-to-pay. The cost varies depending on the type of vehicle. In some countries (e.g. Norway or Japan) there are special passes for frequent trips.
Is it safe to be on the bridge during a storm?
Yes, modern bridges are designed with a huge margin of safety. They withstand hurricane force winds and earthquakes. However, in extreme weather conditions, the speed of traffic can be limited, and in rare cases, the movement is completely blocked.