In the long, hot summer, the battle continues without pause. Currently, during the golden construction period of the third quarter, the upsurge of major project construction in Jiangsu surges on. Two high-speed railways and two river-crossing channels have made new progress.
　　First form traveler segment of the Nantong-Suzhou-Jiaxing-Ningbo High-Speed Railway Wujiang Section poured
　　Recently, the first form traveler segment of the Nantong-Suzhou-Jiaxing-Ningbo High-Speed Railway Wujiang Section was successfully poured, marking that the project construction has officially entered the continuous beam construction stage.
　　The 571# pier continuous beam arch crossing Niuchangjing, constructed by China Railway Tunnel Group, has a main pier 1# block 3 meters long and a beam height of 7.8 meters. It adopts synchronous construction of the 1# and 1#' blocks, with two concrete pump trucks working simultaneously, pouring a total of 116 cubic meters of concrete.
　　Before construction, the construction unit held several special meetings to conduct risk assessments for form traveler construction and continuously optimize the construction plan. During construction, in response to high-temperature weather, a refrigeration system was used to cool the concrete to ensure that the concrete placement temperature met the requirements; technical personnel were arranged to supervise on site throughout the process, strictly controlling the procedures to ensure the quality of concrete pouring.
　　The Nantong-Suzhou-Jiaxing-Ningbo High-Speed Railway is an important part of the coastal railway passenger transport corridor of the national high-speed railway network's "Eight Vertical and Eight Horizontal" main framework, and is also a backbone line of the Yangtze River Delta railway network. At present, the bridge engineering of the Wujiang Section of the Nantong-Suzhou-Jiaxing-Ningbo High-Speed Railway is accelerating the construction of the substructure.
　First cast-in-place beam of the Taizhou Section of the North Yanjiang High-Speed Railway poured
　　Recently, the cast-in-place beam of the 1393#-1394# span of the Tongtaiyang Grand Bridge of the North Yanjiang (Shanghai-Chongqing-Chengdu) High-Speed Railway was poured, which is the first cast-in-place beam pouring in the Taizhou Section of the North Yanjiang High-Speed Railway.
　　This pouring was for the 1393#-1394# pier double-track cast-in-place simply supported box girder, with a total length of 32.6 meters. It adopts beam-column bracket in-situ cast-in-place construction. The bracket support system foundation uses two forms: bridge cap and steel pipe pile foundation. The designed concrete volume is 316.1 cubic meters, and it was completed in a single pouring.
　　To ensure the smooth pouring of the cast-in-place beam, the project department held discussions and disclosure meetings on the pouring plan before commencement, studied the pouring sequence, material preparation, equipment configuration and other preparatory work, and divided responsibilities among management and construction personnel. During pouring, management personnel monitored the whole process and strictly carried out pouring according to the plan disclosure, successfully completing the concrete pouring.
　　Catwalk removal of Longtan Yangtze River Bridge completed
　　With the successful lowering of the last catwalk load-bearing rope, the catwalk removal of the main bridge of the Longtan Yangtze River Bridge was completed. The kilometer-scale "aerial corridor" has fully completed its mission, taking a solid step toward the goal of completing the bridge by the end of the year.
　　As an indispensable "lifeline" in suspension bridge construction, the catwalk is not only a working platform for main cable erection, cable clamp and suspender installation, steel box girder hoisting and other construction, but also an aerial passage connecting the anchorages on the north and south sides of the Yangtze River with the main towers. The catwalk removal construction includes the removal of catwalk portal load-bearing cables, catwalk transfer ropes, catwalk handrail cables, catwalk surface nets, catwalk load-bearing cables, as well as temporary working platforms and displacement frames. The catwalk of the Longtan Yangtze River Bridge uses high-strength galvanized steel wire ropes as load-bearing cables, with one set on each side, a width of 4 meters, and a three-span continuous structure. The removal construction is generally carried out according to the principle of "install first, remove later; install later, remove first," relying on the cooperation of winches, pulley blocks, tower cranes and other mechanical equipment.
　　During the catwalk removal process, facing multiple challenges such as high-altitude and high-risk working conditions and the busy Yangtze River shipping channel, the bridge project construction team organized carefully and planned scientifically, held multiple expert review and safety technical disclosure meetings, and formulated a detailed removal plan; established a safety leading group to monitor the removal operation in real time throughout the process; at the same time, implemented targeted lightning protection, flood prevention, and heatstroke prevention and cooling measures to ensure the safety and health of workers. In addition, the project team actively communicated and coordinated with local governments and relevant departments, effectively avoiding interference of the removal construction with local road traffic and other work areas. After 36 days, the catwalk system removal operation of the Longtan Yangtze River Bridge was completed with high quality and efficiency.
　Steel plate composite girder erection of the south approach of the Jiangyin-Jingjiang Yangtze River Tunnel over adjacent roads completed
　　Recently, the erection of the steel plate composite girder of the south approach of the Jiangyin-Jingjiang Yangtze River Tunnel over adjacent roads was completed, and the project construction achieved breakthrough progress.
　　The overpass over adjacent roads in this construction adopts a 35+55+35 meter continuous steel plate composite girder. The steel plate composite girder is divided into 15 segments longitudinally and assembled on site into 5 hoisting segments (every 2 pieces are connected into one group transversely to form a hoisting unit), and hoisted segment by segment. To ensure safe and efficient construction, the project adopts the assembly and connection method on brackets, sets up a hoisting operation access road at the bridge location, and after the continuous steel plate composite girder segments are transported to the site, a single 280-ton crawler crane is used to directly unload and hoist them onto the bracket positions at the bridge location.
　　The erection section of the steel plate composite girder over adjacent roads is located on a main road in Jiangyin City, with heavy traffic and backed by high-voltage lines. The working site and time are limited, the construction environment is complex, the hoisting procedures are numerous and closely connected, and the construction is difficult. Before erection construction, the project construction team made full preparations, optimized the construction organization and production procedures, strictly implemented the special hoisting construction plan, strengthened on-site high-altitude operation and edge protection measures, actively coordinated with the local service command center, traffic police and other units, and did a good job in traffic organization and coordination, striving to minimize the impact on construction at other parts of the site and on passing vehicles, and completed the steel plate composite girder erection task with high quality and efficiency.