Vasco da Gama Bridge can be safely added to the list of modern wonders of the world. It is located in the northeastern part of Portugal near Lisbon.
Vasco da Gama was known as the Portuguese navigator of the time of the Great Geographical Discoveries. In 1497, the traveler, together with the expedition, went in search of a sea route to South Asia from Europe. The trip was a success: Vasco da Gama discovered the southeastern coast of Africa, from which the further path led to India through the Indian Ocean. In 1499, the expedition returned with great triumph to its homeland, led by the winner. For great services to the fatherland, Vasco da Gama was appointed Viceroy of Portuguese India.
The name of the discoverer was decided to name the bridge connecting the banks of Portugal across the Tagus River (or Spanish Tajo). It is the largest in the entire Iberian Peninsula. The river begins in Spain, passes through all of Portugal and flows into the Atlantic Ocean near the country's capital - the city of Lisbon. The Vasco da Gama Bridge was conceived as a grandiose and large-scale target destination. The feasibility of building a bridge structure was dictated by the urgent need to unloadtraffic flow in Lisbon on the Suspension Bridge named after April 25.
The project of the new bridge was entrusted to develop a group of architects led by Michel Verloge. They faced a difficult task - to connect the banks of the Tagus River, separated by a distance of more than a dozen kilometers, taking into account the high seismic hazard of the area.
Vasco da Gama Bridge: project features
The authors have created a bridge project, consisting of several sections, structurally different from each other. The longest part, twelve kilometers long, looks like a cable-stayed, or hanging, bridge. High reinforced concrete pylons are connected to the road with the help of shrouds - straight steel cables. The height of the pylons reaches one hundred and fifty meters. The largest span of the cable-stayed bridge is four hundred and twenty meters. In addition, the height of the road relative to sea level is forty-seven meters. Such parameters do not prevent the free passage of river vessels.
It is the cable-stayed bridge that ensures the immobility of the roadway. Lightweight pavement is attached separately from the pylons, which prevents the destruction of the bridge during seismic vibrations and storm winds. The design is resistant to wind loads up to two hundred and fifty kilometers per hour. The Vasco da Gama Bridge will withstand four times the force of an earthquake with a magnitude of up to nine in Lisbon in the mid-eighteenth century.
In the initial and final parts, the bridge passes into the viaduct -bridge construction on piles. The distance between the supports in different places is from forty to eighty meters. Piles go under water to a depth of one hundred meters.
The total length of the Vasco da Gama bridge is seventeen kilometers two hundred meters. Taking into account the significant length of the overpass, the roundness of the earth's surface was taken into account in its design in the calculations. Otherwise, there would be a difference of eighty centimeters between the height of the northern and southern extremities of the bridge. The developers have determined the warranty period of the unique design - one hundred and twenty years.
Roads
A thirty-meter-wide motorway was laid across the bridge, along which traffic is organized in four lanes in each direction. Three lanes are used constantly, the fourth is opened at the moments of maximum traffic flow. The speed limit for vehicles is one hundred and twenty kilometers per hour. Only on one of the sections of the bridge is it not allowed to drive faster than one hundred kilometers per hour. In adverse weather conditions, it is required to reduce the speed to ninety kilometers per hour.
To organize preventive measures to maintain the bridge in the proper position, drivers moving towards the capital are charged a toll. The cost is determined depending on the type of vehicle and ranges from two and a half to eleven euros.
Aesthetic features of the bridge
The authors of the project attached great importance to the aesthetic component of the pavementdesigns. In order to minimize the impact on the natural environment, the bridge was built in a wide area of the river.
The viaduct, located on the south side, was built at a considerable distance from the coast, so the coastal zone has undergone minimal bottom damage. The lighting is designed in such a way that the glare from the lamps at night does not reflect on the water surface.
Timing
The Vasco da Gama Bridge was completed in record time. Only three years have passed since the development of the project of the grandiose structure until its commissioning. Half of this period was occupied by preparatory work. More than three thousand builders took part in the construction of the giant structure. The four largest construction companies ensured uninterrupted work with their own technical resources of the latest developments. The construction of a powerful transport artery cost the state nine hundred million euros.
Opening
The grand opening of the large-scale structure took place on March 29, 1998, on the eve of the Expo-98 exhibition. The significant event was timed to coincide with the 500th anniversary of the discovery of the sea route by the traveler Vasco da Gama, after whom the superbridge was named.
Looking at the graceful, huge structure, the viewer gets the impression of airiness and weightlessness of the structure, beckoning into the endless distance. Traveling around Portugal, you should definitely visit such a famous place as the Vasco da Gama Bridge, the photo of which is foreverwill leave in memory the strongest and brightest emotions. The grandiose building strikes with its beauty at any time of the year, equally impressive on a sunny day and dark night, cloudy morning and crimson evening.
Conclusion
The Vasco da Gama Bridge has rightfully received the title of the longest European bridge. Portugal can be justifiably proud of this unique building, which was included by the world community in the treasury of the greatest architectural achievements of mankind at the end of the twentieth century.
