The Longest Bridge in the World
“A bridge can still be built while the bitter waters are flowing beneath.”, Anthony Liccione.
Bridges are a way of connecting beyond natural scopes. It relates to building over the boundaries of landforms and environmental scopes. Bridges connect various lands. The concept is to build over rough waters that one cannot cover through harsh voyages. Although bridges might seem a more relaxed way of commuting from one place to another but as a matter of fact, bridges are not so easy to construct. It requires hundreds of workers and tons of construction material to build a workable bridge that lasts for a lifetime.
There have been many cases of bridges breaking down due to bending loads, and the list goes on. There are many types of bridges like-arch, beam, cable-stayed, suspension, and truss. The most common bridge in use these days is a continuous bridge, these kinds of bridges are economical, but they lack simplicity. The design process is tedious, and the structure is statically indeterminate. Hence this makes the construction of continuous bridges hard; there is a high requirement of labor.
Guinness World Records
The concept of the longest bridge is quite confusing since there are many kinds of bridges scaling the lengths of rivers all around the world. The Guinness world records crowned Lake Pontchartrain Causeway as the longest bridge in the world! But in 2011 another bridge, Jiaozhou Bay Bridge in China, came forward as a bridge which was longer in length than the causeway. To remove any confusion, Guinness World Records put forward two categories of bridges: continuous and aggregate lengths, both of them were for the bridges over water.
Lake Pontchartrain Causeway is the longest bridge in the world under continuous lengths category, and Jiaozhou Bay Bridge is the longest bridge in the world over water in terms of aggregate length. The whole which bridge is the longest caused a lot of controversies, and the segregation of the type of the bridges in defining the longest one ended the disputes that were arising in the United States due to this.
What is a causeway? What is the difference between a causeway and a bridge?
A causeway is basically a raised road or a railway that is built over waters for transportation purposes. A bridge is a structure which includes supports. A bridge is erected over an obstruction including water. A bridge is a track or passageway for carrying traffic. If we take the traditional definition into consideration, a causeway does not allow any passage under it. Traditional causeways were mostly filled roadways. But these days causeways and bridges are sort of combined, in terms of construction and design. This is a reason why the longest bridge in the world is a causeway.
Lake Pontchartrain Causeway
The Lake Pontchartrain Causeway is a twin bridge with two parallel lanes spanning over Lake Pontchartrain in southern Louisiana, United States. Lake Pontchartrain Causeway is also known as the causeway. This bridge is 38.35 km long, and this length relates to the long lane. This length is taken into consideration whenever we calculate the length of the Lake Pontchartrain Causeway. The causeway extends from north to south direction. The southern terminal is in Metairie, Louisiana, a suburb of New Orleans. The northern terminal is in Mandeville, Louisiana. 9,500 concrete piles support this bridge.
The purpose of building the Lake Pontchartrain Causeway was to cut short the time taken by travelers to cross the large saline lake. Initially, travelers had to go across the lake in order to move to the opposite side. This is the main reason why Lake Pontchartrain Causeway came to existence. The whole concept of building the bridges and the beginning of the construction of this meticulous structure goes back to the 1920’s. A proposal in relation to creating artificial islands came forward.
The bridges became links from one artificial island to another. Making bridges to connect lands divided by waters is one of the greatest idea humankind has thought of in the past few decades. The financial support for making bridges to connect islands came from selling home sites present on the islands. In a way, this whole project was to increase living comfort on the two islands. The Louisiana Bridge Company was formed to construct the bridge. The company and the officials used assembly-line processes for bridge building. The company also built a plant for manufacturing on site where all the making and pre-casting took place. The bridge is mainly concrete, and the manufacturing processes took place on the site.
Using pre-stressed concrete: Such concrete is “pre-stressed” by compressing it before it makes its way to the actual structure. They are made by pouring concrete around steel. The steel undergoes stretching under high tension before this process. This increases the resistance of the concrete, and it’s strength as well.
Lousiana has soft soil, this lead to the use of piles for this project. Workers used 54-inch wide, hollow, pre-stressed concrete cylinders as the piles. The size of the piles makes them very strong. Hence the structure has a good support system. Piles are long cylinder-like structures that are driven in the soil at places where the soil cannot take the loads or where the soil is soft. These are the lands where shallow foundations do not work.
The total price to build this bridge is $76 million. The original Causeway was a two-lane span. The original bridge construction cost $46 million. The bridge also has three roads approaching it; these were built along the bridge to support transportation. The traffic on the original bridge resulted in the construction of a parallel two-lane span. It is15 m longer than the original; it costs $30 million. The toll on the causeway is currently 5 USD.
According to CNN Travel, the drive on Lake Pontchartrain Causeway is “a pulse-quickening half-hour drive.” They say that it is one of the scariest drives ever seen! The reason behind this probably due to the fact that you cannot see land mid-ride. Another safety issue is that due to thick fog, driving on this bridge can be dangerous. A lot of speeding takes place on the bridge, to ensure proper security the causeway has its own police force. But nonetheless, it is can also prove to be a great and pleasant drive.