3566 x 2377 px | 30,2 x 20,1 cm | 11,9 x 7,9 inches | 300dpi
Date de la prise de vue:
août 2013
Lieu:
View from San Francisco Bay ferry towards Golden Gate Bridge South Tower, California, USA
Informations supplémentaires:
The Golden Gate Bridge opened in 1937 and until 1964, at 1300 m (4200 ft), was the longest suspension bridge in the world. It carries US Route 101 and California State Route 1 over the Golden Gate Strait at the entrance to San Francisco Bay. An information board, near the Golden Gate Bridge Plaza, illustrates how the Bridge spans the Golden Gate Straits. 'The weight of the roadway, sidewalk, the cars, pedestrians, and bicyclists, is supported by the deck trusses (seen here).The diagonal struts outline the basic structural unit of a truss, the triangle ... inherently strong and stiff. However, the deck trusses are not strong enough to span all the way across the Golden Gate. They are held up every 50 feet (15 metres) by vertical steel suspender ropes. They are the next step in the "load path" ... the term that describes how the weight of the Bridge, including the weight of traffic, is transferred ... to the ground. The deck trusses hand off their load to the ropes, which pull that weight up to the curving main cables. The weight of the deck is suspended from the main cables by these suspender ropes, hence their name. When you look at the tops of the towers of the Bridge, you see where the two cables are supported. All the weight of the roadway and sidewalk deck structure, the traffic, the steel suspender ropes, and the self-weight of the curving main cables , is placed on the tops of the two towers by the cables.... In the Bridge, the towers carry all the gravity loads of the entire suspension structure, from one end to the other, down to the ground. The forces carried down through the steel towers are resisted by the strength of the concrete foundations, which extend into bedrock. The pulling ... forces in the cables are resisted by the ... concrete anchorages at both ends ... also embedded in bedrock. The loads of the Bridge flow through the foundations and reach the earth, completing the load path'.
