Installation of the last cover plate for the North Anchor Anchor completed
Installation of all precast beams on the roof of South Anchor Anchor is completed.
......
Longtan Yangtze River Bridge Project Construction Site
Various construction tasks are in full swing
With the successive completion of the north and south anchorages, the main tower, the cable system and the installation of steel box girders, the construction of the main structure of the main bridge was completed.Construction progress has reached 98%, one step closer to completion and opening to traffic.
The main bridge has finished its "hardening".
Longtan Yangtze River Bridge project from Yizheng City, S356 provincial highway Longshan interchange, south across the Yangtze River, through Nanjing Longtan, ending at S338 provincial highway Longtan interchange, the route length of about 7 kilometers, according to the bidirectional six-lane highway standard construction, the design speed of 100 kilometers / hour.
The main bridge is a single-span suspended steel box girder suspension bridge with a span of 1560 meters, "one span across the river". The north and south towers are group pile foundation, the north anchor is circular ground connecting wall foundation, the south anchor is rectangular sinkhole foundation, and the north and south approach bridges adopt steel-hybrid combined beam structure.
The South Tower across the river is 237.5 meters high, and the North Tower is 235.5 meters high, adopting the landscape modeling of "Double Dragons Playing with Pearls", which forms another bright landscape line above the Yangtze River.
At present, the main bridge of Longtan Yangtze River Bridge has ended "hard installation".The construction of ancillary works, such as transportation and safety facilities, electrical and mechanical installations, and some repairs and improvements, is progressing in an orderly manner.It is expected to be substantially completed by the end of the year.
Anchorages are covered with "heart armor".
Anchorages play a crucial role in the 1560-meter long Longtan Yangtze River Bridge. They are like the "sea god needle", steadily located in the two ends of the bridge, tightly pulling the main cable of the bridge, bear the weight of the entire large-span suspension bridge, to protect the stability and safety of the bridge.
Inside the north anchor chamber, there are 156 cable strand anchorage points, which are the load-bearing structure of the whole bridge, equivalent to the "heart of the bridge". The precise docking installation of each piece of anchor room cover is to give the anchor room with a layer of indestructible "heart armor", for the protection of the stability and safety of the bridge is crucial.
"Anchor chamber covers are categorized into three structural forms, A, B and C, based on their external dimensions, totaling 44 pieces. Among them, the heaviest A type cover plate has 33.6 tons and 16.66 meters, which needs to be lifted to 40 meters for installation. And within the North Anchor Anchor site, the crane crane's station space is limited, the construction is more difficult." The construction unit project manager introduced.
In order to adapt to the special operation environment, the project team innovatively adopted the crawler crane tower type working condition for operation, which effectively solved the problem of restricted lifting space. Through scientific planning and careful formulation of the lifting program, the project overcame the problems of slender and heavy cover plate components and the difficulty of attitude control during lifting, and successfully completed the construction of the main structure of the North Anchor Anchor.
Precise sinking of the "big scale
The South Anchor Anchor is the key bearing structure of the bridge, which consists of a sinkhole and an anchor body. The anchor body on the ground consists of several parts such as anchor block, saddle, side wall, front wall, top cover and decorative block. The whole anchor body is U-shaped with a lateral width of 51.2 meters at the tail end. The lateral width of each side of the front end is 13.2 meters, and the whole length of the anchor body is 66.35 meters in the direction of the bridge.
The height of the caisson, buried deep underground, is about 50 meters, equivalent to 16-story high, 10 standard basketball court size, is a huge "scale" that pulls the whole system tight. In the construction process, the sinkhole needs to be poured 9 times for concrete jointing, and in the process of jointing construction, the sinkhole will be sunk into place 3 times.
The project applies the "air curtain + sand jacket" combined sinking aid technology, supporting the research and development of sinkhole sinking intelligent, automated monitoring system, real-time monitoring of sinkhole structural stress, soil pressure, geometric attitude and other key parameters.Realize "active prediction, intelligent correction" to realize stable and accurate sinking of oversized sinkhole.
The project adopted the underwater three-dimensional sonar sweeping technology to detect the topography of the sinkhole base and provide support for the fine control of sinkhole construction.Realized the "visual, measurable, controllable" of sinkhole construction.According to the measurement, the final center plane deviation and inclination of the south anchor shaft sinking are better than the specification and design requirements.
