Smart tech plays key role in bridge construction

In the prefecture-level city of Jiujiang bordering Jiangxi province's capital of Nanchang, State builders have completed the world's heaviest asymmetric curved cable-stayed bridge, which has the largest swivel weight of its kind.

Builders from China Railway No 4 Engineering Group Co Ltd (CREC4), working on an interchange project of the Jiujiang Fast Transit Line, successfully maneuvered two sections of the swivel cable-stayed bridge traversing Lushan railway station to final positions early Thursday.

Built in two sections, with one section weighing 41,400 metric tons and the other 47,600 tons, they were turned on two gigantic rotating devices to targeted positions and lined up as a whole, said Shi Xifeng, chief engineer of the first phase project from CREC4.

The diameters of the two rotating devices are 7.2 meters and 6.8 meters, respectively, showing the smart engineering and top skills of Chinese builders, Shi said.

The bridge, traversing Lushan railway station — named after the world-renowned Lushan Mountain located in Jiujiang — is an asymmetric curved cable-stayed structure with the widest bridge deck and the largest swivel weight of its kind in the world, he added.

Designed as a two-way eight-lane bridge, the crossing is 465 meters long and 42 meters wide, with an 83-meter-high mother tower and a 77.5-meter-high sub-tower to support 148 intelligent anti-corrosion stay cables of 74 pairs, Shi said.

The longest single stay cable will be 137.54 meters long with a weight of some 20.22 tons, and can sustain a weight of over 950 tons, he added.

The first phase of the transit line, starting from the east side of Jiujiang toll station along the Nanchang-Jiujiang Expressway — which was put into operation on Jan 28, 1996 — has a total length of 15.1 kilometers.

Starting construction on June 20, 2022, the first phase of the Jiujiang Fast Transit Line is the first viaduct expressway in central Jiujiang. Upon completion, it will connect with the Jiujiang Yangtze River Bridge and the rapid transport network including Lushan high-speed rail station, optimizing the layout of Jiujiang's road network, said Chu Lingpeng, publicity chief of CREC4 Fifth Engineering Co Ltd, which is building the bridge.

"We are installing three magnetic flux sensors in each anchorage at the tower end for a stay cable, and there are 444 magnetic flux sensors on the whole bridge, paired with two magnetoelastic instruments for data measurement, rendering the stay cable an intelligent structure," Shi said.

"Compared with traditional cables, intelligent cables are more accurate in the tensioning process during installation, allowing timely examination and measurement during the bridge's later inspection and maintenance, and better ensuring cable force safety of the bridge," Shi added.