斜拉橋及懸索橋

現(xiàn)代斜拉橋的復(fù)興是第二次世界大戰(zhàn)后橋梁發(fā)展史上最偉大的成就之一。斜拉橋在60年代初傳入我國(guó)后，上海和四川兩地于1975年建成了糧作試驗(yàn)性的鋼筋混凝土斜拉橋，即主跨分別為54m的新五橋和75.8m的云陽(yáng)湯溪河橋。

1977年起，我國(guó)進(jìn)入了改革開(kāi)放的新時(shí)期，TRANBBS交通發(fā)展的需要推動(dòng)了大跨度斜拉橋的建設(shè)。1982年建成的跨度為220m的山東濟(jì)南黃河橋可以認(rèn)為是我國(guó)第一階段學(xué)習(xí)建造斜拉橋的成功總結(jié)。

至80年代，斜拉橋迅速在全國(guó)各地推廣，許多省市建造了30余座各種不同類(lèi)型的斜拉橋。如主跨長(zhǎng)度達(dá)到260m的天津永和橋和288m的山東東營(yíng)黃河橋（后者是我國(guó)第一座鋼斜拉橋）；廣州市海印橋的35m最大橋?qū)捄碗p薄壁墩單索面體系；廣東南海九江大橋采用5000kN浮吊的快速懸拼TRANBBS施工；重慶石門(mén)大橋主跨為230m的不對(duì)稱(chēng)布置獨(dú)塔斜拉橋和采用最長(zhǎng)懸臂澆注施工，以及1990年竣工的長(zhǎng)沙湘江北大橋的輕型掛籃懸澆施工和美麗造型等都各具有特色，成為這一時(shí)期斜拉橋建設(shè)的代表性工程。

進(jìn)入90年代，我國(guó)的斜拉橋建設(shè)出現(xiàn)了一個(gè)新的高潮。以上海南浦大橋的建成（1991年）為起點(diǎn)，一大批跨度超過(guò)400m的斜拉橋正在建造、TRANBBS設(shè)計(jì)或TRANBBS規(guī)劃之中。其中，上海楊浦大橋是繼南浦大橋后的又一座602m記錄跨度的結(jié)合梁斜拉橋。可以預(yù)料，在本世紀(jì)的最后10年中，中國(guó)的斜拉橋建設(shè)，無(wú)論在規(guī)模上和發(fā)展速度上都將取得令世界矚目的偉大成就。

我國(guó)現(xiàn)代懸索橋的建造起步較遲，60年代在西南山區(qū)建造了一些跨度在200m以內(nèi)的半加勁式單鏈和雙鏈?zhǔn)綉宜鳂颍渲休^著名的是1969年建成的重慶朝陽(yáng)大橋；1984年建成的西藏達(dá)孜橋，跨度達(dá)到500m。90年代的交通建設(shè)高潮使我們終于迎來(lái)了建造現(xiàn)代大跨度懸索橋的新時(shí)期。跨度為452m的廣東汕頭海灣大橋采用混凝土加勁梁；廣東虎門(mén)大橋?yàn)榭缍冗_(dá)888m的鋼箱梁懸索橋；主跨超過(guò)1200m的江陰長(zhǎng)江大橋正在設(shè)計(jì)之中。3座懸索橋的同時(shí)建造將使我國(guó)的橋梁科學(xué)TRANBBS技術(shù)迅速趕上世界先進(jìn)水平。

The revival of modern cable-stayed bridges is one of the greatest achievements in bridge ebgineering after World War II.

Cable-stayed bridges were first introduced into China in the early sixties. Two trial bridges, the Xinwu Bridge with a main span of 54m in Shanghai and the Tangxi Bridge with a span of 75.8m in Yunyang, Sichuan Province -- both are reinforced concrete cable-stayed bridges --were completed in 1975.
Since 1977 when China entered a new era with its reform and open policy, with the traffic development, China's bridge engineering has made great strides in the construction of long-span cable-stayed bridges. The Jinan Bridge across the Yellow River with a main span of 220m, which was completed in 1982, can be regarded as a successful achievement of the first stage -- the learning stage -- in the history of China's

cable-stayed bridge construction.

In the eighties, the construction of cable-stayed bridges developed rapidly over a wide area in China. More than 30 bridges of various types were erected in different provinces and municipalities, for example, the Yonghe Bridge in Tianjin, which has a span as long as 260m, and the Dongying Bridges in Shandong Province, whose span reaches 288m, the latter being China's first steel cable-stayed bridge. In addition, the Haiyin Bridge in Guangzhou with its 35m-wide deck, single cable plane and double thin-walled pylon piers; the Jiujiang Bridge in Nanhai of Guangdong Province, which was erected by a floating crane with a capacity of 5000kN; the Shimen Bridge in Chongqin, Sichuan Province, having an asymmetrical single cable plane arrangement and a 230m cantilever cast-in-situ; and the attractive-looking Xiangjiang North Bridge in Changsha of Hunan Province, completed in 1990 with light travlling formwork -- all are the representatives in this period with respective features.

At the beginning of this decade, with the completion of the Nanpu Bridge in Shanghai in 1991, a new high tide of construction of cable-stayed bridges began to surge in China. Now, a large number of cable-stayed bridges with a span of over 400m are under design and contruction. The most outstanding one is the yangpu Bridge with a record-breaking span of 602m, another composite deck cable-stayed bridge in China will have attracted world attention not only for its large scale but for its speedy development as well.

Comparatively speaking, the contruction of modern suspension bridges in China started rather late. In the sixties, some flexible suspension bridges with spans less than 200m were built in the mountain areas of southwestern China, the Chaoyang Bridge in Chongqin, Sichuan Province being the most famous one. However, the Dazi Bridge in Tibet completed in 1984 has a span as long as 500m.

The upsurge of traffic engineering construction in the ninties led to a new stage of modern suspension bridges. The Bay Bridge in Shantou, Guangdong Province will have a 452m concrete stiffening girder; the Tigergate Bridge will be a steel box girder suspension with a main span of 888m; the Jiangyin Bridge over the Yangtze River, whose main span is 1385m, is now completed. The simultaneous construction of the three suspension bridges is a convincing evidence that China's bridge science and technology will soon catch up with the advanced world level.