Engineering feats:

Bridging the great divide

The vast advancements made in the field of technology and the improvement of machinery has made it possible for man to display his engineering feats in the form of mega structures such as tall sky scrapers and intricately designed bridges many of which have become world record holders. Today we feature a few of these awesome bridges. What is a bridge?It is defined as a structure that is built to cross physical barriers between two places such as bodies of water, hills, valleys or roads in order to serve its purpose as a passage or route for travellers.

The design as well as the type of bridge usually varies depending on its function, nature of the terrain and as well as the setting where the bridge is constructed. The budget as well as the materials to be used can also influence the total outcome of the bridge. These days, bridges can be seen connecting thousands of places from all over the world. These incredible structures have paved the way for easier transportation and access from one place to another.

However, just like any other buildings or constructions, there are also record holders for the different bridges in the world. As for the longest, China’s Danyang Kunshan Grand Bridge still remains undisputed. Let’s check out some of the engineering marvels.

The Danyang Kunshan Grand Bridge

Recognised as the longest of its kind in the entire world, the Danyang Kunshan Grand Bridge is located in the city of Qingdao, which is allocated in the Shandong province in the East side portion of the Republic of China. When the bridge was completed, it became the world’s longest bridge with a whopping length of 164,800 metres or 164.8 kilometres and a span of 260 feet. “Span” refers to the longest spans without any ground support. This massive and incredible man-made structure was completed in 2010 after four years and was only opened to the public in 2011. This huge project costs approximately 8.5 billion dollars and has employed roughly 10,000 workers on site. This bridge was primarily made in order to solve railway traffic in the area.

The Danyang Kunshan Grand Bridge is actually made of different or several bridges. One of its parts is called as the Qingdao Haiwan Road Bridge, which is a portion of the Danyang Kunshan Grand Bridge and is also recognised as the longest bridge over water. This bridge has a length of 42.5 kilometres or 26.5 miles and runs from Qingdao of East China’s Shandong Province to the suburban Huangdao district over the Jiaozhou Bay.

Because of this, China instantly became the country with the most number of longest bridges in the world.

In fact, China holds three of the world’s longest bridges namely the Danyang Kunshun Grand Bridge, the Tianjin Grand Bridge (113,700 kilometres) and the Weinan Weihe Grand Bridge with a length of 79,732 kilometres.

The bridge also consists of over 450,000 tons of steel structure. According to Chinese officials, the Danyang Kunshan Grand Bridge is a very sturdy infrastructure that can withstand strong typhoons, magnitude 8 earthquakes and an impact that is equal to a 300,000 ton vessel.

As soon as this bridge was completed, it immediately took the crown from the previous title holder, which is the Lake Pontchartrain Causeway in Louisiana, USA. This bridge is measured 24 miles long and is dangling over the Pontchartrain. Because of this Chinese innovation, China now holds both the longest land and water colossal bridges.

Baluarte Bicentennial Bridge

The world’s tallest suspension bridge opened in Mexico in January this year spanning a ravine higher than New York’s Empire State building and Paris’ Eiffel Tower. At 403 metres or 1,322 feet tall, the Baluarte Bicentennial Bridge connects between the northwestern states of Sinaloa and Durango in the Sierra Madre Occidental mountains.

The gravity-defying ribbon of concrete, the Baluarte Bridge (Puente Baluarte), officially the Baluarte Bicentennial Bridge (Puente Baluarte Bicentenario) is a cable-stayed bridge in located between the municipalities of Concordia in Sinaloa and Pueblo Nuevo in Durango, along the Durango–Mazatlán highway in mexico.

The bridge has a total length of 1,124 m (3,688 ft), with a central cable-stayed span of 520 m (1,710 ft).With the road deck at 403 m (1,322 ft)2] above the valley below, the Baluarte Bridge is the highest cable-stayed bridge in the world, and the second-highest bridge overall. Construction of the bridge began in 2008.

The bridge’s four-lane roadway, 20 metres (66 ft) wide by 1,124 metres (3,688 ft) long, is supported at a height of 403 metres (1,322 ft) above the Baluarte riverbed by 12 piers, two of which are also pylons (towers). Each of the two pylons measures 18 by 8.56 metres (59 by 28.08 ft) at its base, widens in the centre to carry the roadway before tapering upwards to 8 by 4.10 metres (26 by 13.45 ft) wide at its top; the taller, P5, is 169 metres (554 ft) high. 76 steel cables pass over saddles in the pylons to form 152 suspenders in a two plane semi-fan layout.

It crosses a gorge in the Sierra Madre Occidental mountains with a clearance of 390 metres (1,280 ft) below the deck, substantially taller than the Eiffel Tower. Its clearance is 120 metres (390 ft) higher than that of the previous record-holder, France’s Millau Viaduct, which has a clearance of 270 metres (890 ft).The bridge’s central span, 520 metres (1,710 ft) long, is also the longest cable-stayed span in North America, 37 metres (121 ft) longer than that of the John James Audubon Bridge in St. Francisville, Louisiana.

By January 2012, the bridge’s construction had required the use of 1,500 workers and engineers, 12,000 tonnes (11,800 long tons; 13,200 short tons) of steel and 90,000 cubic metres (118,000 cubic yards) of concrete, 447,000 cubic metres (584,700 cubic yards) of rock were excavated to lay the bridge’s foundations.

The Baluarte Bridge construction is part of an 18 billion peso (US$1.44 billion) project to build a new highway connecting Durango with Mazatlán across some of Mexico’s most rugged mountains.

The cost of the bridge itself has been put at 2.18 billion pesos (US$158.7 million) It will replace a notoriously dangerous road over the mountains, which are known locally as “the Devil’s Backbone.”

The old road was built in the 1940s in terrain so difficult that mules had to be used to bring in supplies for the construction workers. It is the only crossing through the mountains for 500 miles (800 km).

The new Mazatlán–Durango highway will include 63 tunnels and 32 bridges, eight of which will be over 300 metres (980 ft) high. The Baluarte Bridge was inaugurated by President Calderón on 5 January 2012.

Officials from Guinness World Records were on hand at the inauguration ceremony to certify the bridge as the world’s highest; at the time it was about 86 per cent complete.

Its official name as the “Bicentennial” bridge refers to the 2010 bicentenary of the Mexican declaration of independence from Spain at the start of the Mexican War of Independence in 1810.

Aizhai Extra Large Suspension Bridge

China opened the world’s highest and longest tunnel-to-tunnel suspension bridge in the mountainous region of Hunan province. The Aizhai Extra Large Suspension Bridge, 355 metres above the Dehang Canyon, is part of the 64-kilometre-long Jishou-Chadong Expressway and links tunnels that are 1,176 metres apart. Work started on the engineering feat in October 2007 and the bulk of the work finished at the end of last year.

The bridge was officially opened on March, 2012.The bridge connects two cities–Chongqing Municipality to Changsha city–and runs a whopping 3,858 feet, and uses 2 tunnels cutting down travel time between the two cities, which used to be several days, to only eight hours. Construction on the bridge took fouryears. Pedestrians, can also walk along the suspension bridge, with 1,888 lights guiding their way.

The Aizhai suspension bridge has a main span of 1,176 metres and soars 335m above the ground. It was built as part of an expressway from southwest China’s Chongqing Municipality to Changsha city in Hunan.

 Work started on the engineering feat in October 2007.

Driving across the bridge, which links two tunnels together, drivers are offered a breathtaking view of the Dehang Canyon. The Aizhai bridge, the world’s highest tunnel to tunnel bridge, at 336 metrer - high (1,102 feet) and spanning 1,176 metres (3,858 feet),i is also the fourth suspension bridge in China to cross a valley so wide it seems to be connecting two mountain rang.Of the world’s 400 or so highest bridges, none has a main span as long as Aizhai.

Jiaozhou Bay Bridge

Almost an year ago China declared opened the world’s longest brige over water, the Jiaozhou Bay bridge also called the Qingdao Haiwan Road Bridge, which is estimated to have cost more than 10 billion yuan ($1.5 billion and took four years of construction work. It reported that at least 10,000 people worked in two teams around the clock on the span’s construction. Stretching across the wide blue waters of Jiaozhou bay, the vast Jiaozhou Bay bridge which is 26.4 miles long and 110-feet-wide, according to Guinness World Records, links China’s port city of Qingdao with an airport built on a nearby island and the industrial suburb of Huangdao. The bridge which has six lanes shortens the journey between Qingdao and Huangdao by about 18 miles, cutting travel time from 40 minutes to 20 minutes. The bridge is expected to carry more than 30,000 cars a day.

The Y- shaped bridge, which is supported by more than 5,000 pillars and reportedly used up about 81 million cubic feet of concrete — enough to fill 3,800 Olympic-sized swimming pools and about 450,000 tons of steel — enough for almost 65 Eiffel Towers is said to be earthquake- and typhoon-proof.It is designed to withstand the impact of a 300,000-ton vessel.

According to the Guinness World Records, the previous longest bridge over water was the Lake Pontchartrain Causeway in Louisiana. The Chinese bridge is more than 2.5 miles longer.

However, this bridge is far short of the longest in the world. The Danyang–Kunshan Grand Bridge, which runs over land on the Beijing-Shanghai rail route, is 102 miles long, according to Guinness.The Jiaozhou Bay bridge will be eclipsed in 2016 by yet another Chinese bridge, which is being built to link Hong Kong with Macao and Guangdong.

More on bridges next week