london tower bridge, the golden gate bridge, yangpu bridge 的

london tower bridge, the golden gate bridge, yangpu bridge 的英文简介
三座大桥的英文简介!
每座至少两百字,谢谢拉

后两个有需要的话只能自己翻译好吗
1. TOWER BRIDGE LONDON
Originally, London Bridge was the only crossing over the Thames. As London grew, so more bridges were added, but these were all to the west of London Bridge, since the area east of London Bridge had become a busy port. In the 19th century, the east end of London became so densely populated that public pressure mounted for a bridge to the east of London Bridge, as journeys for pedestrians and vehicles were being delayed literally by hours.
Finally in 1876, the Corporation of London, who were responsible for that part of the Thames, decided that the problem could be put off no longer. Tower Bridge was completed in 1894, after 8 years of construction. However, many people don't realise why it is so different from London's other bridges.
How a Design was Chosen
The big problem for the Corporation of London was how to build a bridge downstream from London Bridge without disrupting river traffic activities. To get as many ideas as possible, the "Special Bridge or Subway Committee" was formed in 1876, and opened the design of the new crossing to public competition.
Over 50 designs were put forward for consideration, some of which you can see if you visit The Tower Bridge Exhibition. However, it wasn't until October 1884 that Horace Jones, the City Architect, in collaboration with John Wolfe Barry, offered the chosen design for Tower Bridge as a solution.
The Building of the Bridge
It took 8 years, 5 major contractors and the relentless labour of 432 construction workers to build Tower Bridge.
Two massive piers had to be sunk into the river bed to support the construction, over 11,000 tons of steel provided the framework for the towers and walkways. This was then clad in Cornish granite and Portland stone, both to protect the underlying steelwork and to give the bridge a more pleasing appearance.
How it Works - Then Now
When it was built, Tower Bridge was the largest and most sophisticated bascule bridge ever built （"bascule" comes from the French for "see-saw"）. It was a hydraulically operated bridge, using steam to power the enormous pumping engines. The energy created was then stored in six massive accumulators so that, as soon as power was required to lift the bridge, it was readily available. The accumulators fed the driving engines, which drove the bascules up and down. Despite the complexity of the system, the bascules only took about a minute to raise to their maximum 86 degrees.
Nowadays, the bascules are still operated by hydraulic power, but since 1976 they have been driven by oil and electricity rather than steam. The original pumping engines, accumulators and boilers are on show as part of The Tower Bridge Exhibition, and you can also see the current machinery and control cabins when you come on a "Behind The Scenes Tour".
最初,伦敦桥（London Bridge）是唯一横跨泰晤士河的一座桥梁.随着伦敦的发展,河面上开始出现更多的桥梁.但它们都在伦敦桥以西,因为伦敦桥以东的区域已经成为一个繁忙的港口.19世纪,伦敦东区的居住密度变得非常之高,这使得步行或驾车穿越泰晤士河常常要花费好几个小时,公众因此施压要求在伦敦桥以东建造一座大桥.
最终,在1876年,当时负责泰晤士河该段的伦敦公司（Corporation of Londaon）认为这一问题已不能再拖延.塔桥（Tower Bridge）在历经8年的建造后于1894年竣工.然而,许多人并不明白为什么这座桥和伦敦的其他许多桥如此不同.
如何选中该设计
伦敦公司当时面临的主要问题是如何在伦敦桥的下游建造一座桥梁,同时不会影响到内河运输.为了获得尽可能多的主意,“特别桥梁或地铁委员会”于1876年成立,并举办了面向公众的设计比赛,设计比赛的对象就是横跨泰晤士河的新建筑.
超过50幅设计被纳入最终考虑.如果你去参观塔桥展览（The Tower Bridge Exhibition）的话,能够看到其中的一些.但是,直到1884年10月城市建筑师Horace Jones与John Wolfe Barry提交了他们的合作设计,塔桥的最终中选方案才水落石出.
塔桥的建造
塔桥的建造动用了5家主承包商和432个建筑工人不间断的工作,历时8年才最终完成.
两块巨大厚重的桥墩被沉入河床以支撑整个建筑,超过11,000吨钢铁被用来构建塔身和人行道.随后用考尼什花岗岩（Cornish granite）和波特兰石（Portland stone）将其包裹住,这样既能保护内部的钢铁架构,又使大桥看起来更加漂亮.
塔桥过去和现在都如何运作
塔桥竣工时,是当时最大最精密的平衡活动结构（“平衡活动结构”一词源自法语中的“秋千”,以下简称吊桥）.它是一座水压控制的桥梁,利用蒸汽来驱动巨大的泵.由此产生的能量被储藏于6个大型蓄电池中,然后传输给驱动吊桥上上下下的操纵引擎.尽管整个系统非常复杂,但有了这些能量,就可以随时升降吊桥了.只需大约一分钟的时间,整个吊桥就能上升到其86度角的上限.
现在,吊桥仍然在水压的控制下运作.但从1976年起,其驱动力已由原来的蒸汽变更成石油和电力.塔桥当初使用的泵、蓄电池和锅炉现在作为塔桥展览的一部分对外展出.如果你参加“塔桥幕后之旅（Behind The Scenes Tour）”,你还能看到塔桥现在使用的机器和控制室
2. The Golden Gate Bridge is an iconic, sometimes cliched, image in the repertoire of San Francisco photos. It's difficult to imagine the Golden Gate, the entrance to our Bay, without the International Orange span that's come to characterize the ocean side of the city.
Of course the many peoples who populated the area for centuries before the Spanish arrived -- the Ohlone, the Coast Miwok -- could argue that the Golden Gate was as spectacular in its pristine state as it is now with the bridge that beckons entry.
Which is to say that it's tough to critique the stunning setting where the bridge makes its home. And we can be grateful that the bridge's credited designer, Joseph B Strauss, had the wherewithal to erect a structure that didn't mar the natural beauty of its San Francisco Bay anchor points . . . even if his initial design with hybrid cantilever was ultimately refined with the help of architects Irving and Gertrude Morrow.
3.yangpu bridge
The Yangpu Bridge (杨浦大桥), in Shanghai, China, is among the world's longest bridges, with a total length of 8,354 meters. Its longest span of 602 m makes it the fourth largest cable-stayed bridge in the world. It carries the Inner Ring Road from the Yangpu District in Puxi to the Pudong New Area. It was completed in September 1993 and opened in October.
The bridge was designed by the Shanghai Municipal Engineering Design Institute, Shanghai Urban Construction College, and Shanghai Urban Construction Design Institute, with assistance from Holger S. Svensson. It was built by the Shanghai Huangpujiang Bridge Engineering Construction company.
Its two pylons reach 223 m in height. The highest ship clearance is 48 m, a necessity due to the heavy river traffic.
As of 2006, it carries more than 100,000 vehicles per day across its six lanes.
The bridge was originally unpainted; it was coated with red paint for the millennium. The name Yangpu Bridge (杨浦大桥) inscribed on each pylon was originally hand-written by Deng Xiaoping.