Xintian Yangtze River Bridge hits a domestic construction record with more than 200 tons of heavy steel box girder relayed in the air on a 100-meter river surface
China News Service, Chongqing, April 7th (Chen Hongsheng, Wang Ruoqing, Liu Xianglin) On the rippling Yangtze River, 220 tons of heavy steel box girder achieved continuous two swings at an altitude of 100 meters, completing the “air relay” precise positioning on the bridge Surface mounting point. On the 7th, the largest span steel box girder suspension bridge under construction in the Three Gorges Reservoir area, Chongqing Xintian Yangtze River Bridge South Bank Section 1, completed the 72-meter long-distance construction link in the air, creating a new domestic record for this construction.
The picture shows the steel box girder is hoisted vertically in the middle of the river. Photographed by Chen Hongsheng
The Xintian Yangtze River Bridge, with a total length of 1,770 meters and a main span of 1,020 meters, has undergone two years of construction. From the beginning of April 2021, the steel box girder during the construction of the superstructure will be lifted in the sky. “. Just like the “swing” construction method, it tests the bridge construction team’s technological innovation research strength and safety risk management and control capabilities.
The picture shows the successful completion of the first swing. Photo by Chen Hongsheng
Zeng Xiongxing, deputy manager of the Xintian Yangtze River Bridge Project Department of China Communications First Public Administration and Third Company, introduced that the deck of Xintian Yangtze River Bridge consists of 57 sections of steel box girder. According to the topographical conditions on both sides of the strait and the actual factors of the water level of the Yangtze River, the steel box girder on both sides of the strait needs to be moved by 5 sections for a total of 10 sections. Due to the low water level during the hoisting construction in the bank slope area, the south bank slope area is nearly 70 meters long, and the positioning and hoisting of ships in the bank slope area brings extremely high implementation difficulty and great safety risks.
The picture shows the first swing of the steel box girder in progress. Photo by Chen Hongsheng
It is understood that the No. 0 section steel box girder weighing 212.9 tons on the south bank of the bridge was the first to move on April 3rd. The project team used a cable crane to lift the steel box girder from the positioning ship vertically from the river surface in advance. After the long sling went through two consecutive swings and an aerial relay, it was then towed by a horizontal traction of 16 meters and a single translation before the safe hoisting was completed. Bit. This method of “hanging front and supporting back” made the total span of aerial swings reach 88 meters, setting a record for the construction of long-distance swings in China. Compared with the previous conventional construction method of erecting a floor stand in the bank slope area, the innovative method adopted this time has achieved the technical accuracy requirements and high safety guarantee during the swaying process, saving construction costs by more than 5 million yuan.
The picture shows the second swing of the steel box girder in progress. Photo by Chen Hongsheng
Zeng Xiongxing said that the ten-segment steel box girder swaying process adopts the principle of “first south and then north, symmetrical hoisting”, and it is expected that all hoisting tasks will be completed by the end of April. At that time, it will be transferred to the steel box girder welding, main cable winding wire coating and bridge deck paving processes.
p >The picture shows workers replacing the clamps of the cross-cable hoist. Photo by Chen Hongsheng
As a key control project of the national expressway network from Enshi to Guangyuan Expressway-Wanzhou Xintian to Gaofeng section, the Xintian Yangtze River Bridge is expected to be completed and opened to traffic around June 2022. At that time, the Three Gorges Reservoir area will add another large channel across the river.