Content area
Full text
The city of Nanjing's second bridge across the Yangtze River features the first use of an epoxy asphalt deck pavement in China and one of the longest cable-stayed spans in the world. By Yongning Dai and Man-Chung Tang
With a population of roughly 6 million, Nanjing is one of the largest cities in China. Most of the city is on the southern side of the Yangtze River, but the northern side is developing rapidly. The first crossing over the Yangtze River, completed in 1968, was the first major bridge in China to be designed and built entirely by the Chinese, and it has been a source of national pride ever since. Until recently, it was the only link between the two segments of the city. To alleviate the traffic congestion that has accompanied the city's growth, a new bridge, the Nanjing Second Yangtze River Bridge, has now been built about 11 km downstream.
At the location of the new bridge, Bai Gua Island splits the river into two branches. Consequently, the bridge project, with a total length of about 12 km, consisted of two crossings connected by a roadway section at grade. The 2,172 m long northern crossing is a prestressed-concrete box girder with three navigation spans of 165 m each, which were erected using a cast-in-place balanced-cantilever method.
The main section of the 2,958 m long southern crossing, on the other hand, consists of a 1,238 m long cable-stayed bridge, which includes a 628 m center span, two 246.5 m side spans, and two 58.5 rn flanking spans. The center span is the longest cable-stayed bridge span in China and the third longest in the world, exceeded only by the 856 m span of France's Normandie Bridge and the 890 rn span of Japan's Tatara Bridge. The deck is 37.2 m wide and carries six lanes of traffic. The structure has a longitudinal slope of 2.8 percent and a transverse slope of 2 percent from the centerline of the bridge. Its vertical navigational clearance is 24 m above the high water level, and the minimum navigation channel width is 380 m.
The $410-million bridge was designed by the Highway Planning and Design Institute a government agency based in Beijing-and the project was managed...