In the prefecture-level city of Jiujiang, which borders Jiangxi province's capital of Nanchang, State-owned builders are adopting smart engineering technology to boost construction on the world's heaviest asymmetric curved cable-stayed bridge.

Builders from China Railway No 4 Engineering Group Co Ltd (CREC4), working on an interchange project of the Jiujiang Fast Transit Line, on Monday hoisted the first stay cable for the swivel cable-stayed bridge traversing Lushan Station, named after the city's renowned Lushan Mountain.

The stay cable, 25.02 meters long and weighing some 2.66 metric tons, is composed of 73 steel strands with each strand sustaining a weight of some 8 tons, said Shi Xifeng, chief engineer of the first phase CREC4 project.

The bridge type has the widest bridge deck and the largest swivel weight of its kind in the world, he added.

"We are installing three magnetic flux sensors in each anchorage at the tower end for stay cables, and there are 444 magnetic flux sensors spanning the bridge, along with two magnetoelastic instruments for data measurement to make the stay cables intelligent," 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 work, and better ensuring the cable force safety of the bridge," he said.

The first phase of the Jiujiang Fast Transit Line project, starting from the east side of Jiujiang Toll Station of the Nanchang-Jiujiang Expressway — which was put into operation on Jan 28, 1996 — has a total length of 15.1 kilometers.

Designed as a two-way eight-lane bridge, the structure is 465 meters long and 42 meters wide, and has an 83-meter-high mother tower and a 77.5-meter-high sub-tower to support 148 intelligent anticorrosion 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.

Starting construction on June 20, 2022, the first phase of the fast transit line is the maiden viaduct expressway in central Jiujiang. Upon completion, it will connect with the Jiujiang Yangtze River Bridge and the rapid transport network of the Lushan high-speed railway 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.

The successful hoisting of the first stay cable has laid a solid foundation for the expected turn of the swivel cable-stayed bridge in late September, he said.

The bridge is currently being built in two sections, with one section weighing 41,400 tons and the other 47,600 tons, and the two sections will be turned on two gigantic rotating devices by then, Chu said.