Hoisting the steel cofferdam at the first section of Pier 2 of Changtai

Update time:2021-09-26 Number of views:881 Return to list>>

the pouring of the first 0 block on Hezhou Bank of Zhuhai Jinhai bridge is completed

On the morning of November 27, the main bridge of Huanghu bridge, the longest Lake crossing bridge in Anhui Province, was successfully closed. The successful closure of the main bridge of Huanghu bridge lays a solid foundation for the opening of Huanghu bridge at the end of December 2021 as planned.

At the construction site of Huanghu bridge, machinery roared, and the project builders were pouring concrete for the closure section of the main bridge. Huanghu bridge starts from xiacang town in the north and Huayang River Farm in the south, with a total length of 7.5km and a main bridge of 230m. Since this year, all the staff of the project have overcome the construction difficulties such as epidemic situation and rising water level in the inner lake, optimized the construction scheme and adopted various measures to ensure the smooth closure of the main bridge of Huanghu bridge in the early stage of ensuring safety and high quality.

Huanghu bridge is the longest Lake crossing bridge in Anhui Province, and it is also an important link in the construction of wetland infrastructure of Huayang River and lake group. The construction of the bridge will be of great significance to promote the co construction of reclaimed land and the integration of farms into local economic development, and regulate the ecological environment and sustainable development of Huayang rivers and lakes. It is expected that after the completion of Huanghu bridge, the traffic between xiacang town and Huayang River farm will be shortened from the original 50 minute drive to 15 minutes.


the steel cofferdam at the first section of Pier 2 of Changtai Yangtze River Bridge is hoisted in place

On November 28, the steel cofferdam at the first section of Pier 2 of Changtai Yangtze River Bridge was successfully hoisted at the pier position, marking a new stage in the underwater foundation construction of Tianxingzhou special channel bridge of Changtai Yangtze River Bridge.

In the morning of that day, at the bridge construction site, the hulls of two 600 ton and 800 ton floating cranes were fixed side by side, and the transport ship docked steadily at the downstream side of the drilling platform. With the command of the commander, the floating crane ship lifted the steel cofferdam and moved smoothly to move the behemoth accurately. It is understood that the cofferdam of Pier 2 is equivalent to the size of 3.7 standard basketball courts. It is hoisted in two sections. This time, the hoisting of the bottom section steel cofferdam is completed, with a height of 13.7m and a weight of 775 tons.

Tianxingzhou special channel bridge, with a main span of 388m, is the largest highway railway steel truss arch bridge in the world. The construction of 1#-4# pier bearing platform adopts double wall steel cofferdam for protection construction. On the one hand, the steel cofferdam is used as the water retaining structure during the bearing platform construction, on the other hand, it is used as the formwork for concrete pouring of the bearing platform, and its section form is consistent with the plane layout of the bearing platform. The first section of the steel cofferdam was successfully hoisted in place, officially opening the prelude to the construction of the main tower pier bearing platform, and laying a good foundation for the next cofferdam heightening, main pier bottom sealing and bearing platform construction of Changtai Yangtze River Bridge. It is expected to complete the bottom sealing construction of four cofferdams by the end of February 2021 and the construction of four bearing platforms by the end of June 2021.


the pouring of the first 0 block on Hezhou Bank of Zhuhai Jinhai bridge is completed 

On November 28, with the last truck of concrete pouring, the concrete pouring of block 0# of 75# pier on the left side of Hezhou Bank of Zhuji intercity Jinhai bridge was completed, marking that Hezhou bank has entered the superstructure construction stage.

The Hezhou Bank of the bridge is located in the reclamation area (isolated island) of Hezhou island. There is no electricity or water, and there is no road to the construction area. The construction environment is very difficult. As the channel grade of Modaomen waterway is grade I, the trestle needs to reserve a channel, which cannot directly lead to Hezhou reclamation area from Hengqin. According to the construction organization design, 1.1km trestle and 13 underwater drilling platforms need to be built on Hezhou bank. The input of steel structure is about 15000 tons. All steel structure materials need to be transported to the construction location by ship from Hengqin bank.

However, there are many construction piers at Hezhou side, and there are simultaneous construction of pile foundation, cofferdam, bearing platform, pier body, box girder, steel beam and other parts, involving a variety of processes carried out at the same time on adjacent working faces, which makes it difficult to manage the site.

In addition, there are many bridge structures and large quantities within the construction scope, and the corresponding investment in personnel, materials, large machinery and equipment is huge. During the peak period of construction, there will be more than a dozen sets of hanging baskets working at high altitude at the same time, so the risk and difficulty of safety and quality management are high. The underground water in the bridge area has sulfate erosion and magnesium salt erosion, and the chemical environmental action level is high, The grade of salt crystallization damage and chlorine salt environmental action is high, and the bridge concrete adopts high-performance marine durability concrete. In the absence of hydropower, Hezhou bank only relied on generators to generate electricity in the early stage, and completed the construction tasks of 1.1km trestle and some drilling platforms. Through the unremitting efforts of the on-site workers, the problem of power and water consumption was solved by laying submarine cables and water pipes, which laid a solid foundation for the construction of the main structure of Hezhou bank.

The total number of pile foundations on Hezhou bank is 323, of which 308 have been completed and the remaining 15; 51 cushion caps are designed and 32 have been completed; 51 pier shafts have been designed and 24 have been completed.

Jinhai super major bridge is the first highway and railway dual-purpose bridge built at the estuary of the Pearl River Delta. The main bridge is a cantilever steel box girder multi tower rigid frame system highway and railway cable-stayed bridge on the same floor. The bridge is 1369m long and 49.6m wide. There is a double track 160km / h intercity Railway in the middle, and a six lane 100km / h Expressway on the left and right sides of the same floor.


Gaolingtou water storage bridge of Jingwen Expressway enters the upper tower column construction stage

At 7:30 on November 29, after 24 hours of continuous pouring, the second pouring of the lower cross beam of the z2# main pier of Gaolingtou water reservoir bridge of Jingwen Expressway Control Project was completed, marking the successful completion of the construction of the main tower 0# block. At present, the tallest concrete cable-stayed bridge in Zhejiang Province has entered the construction stage of the upper tower column.

Gaolingtou water storage bridge is a tower pier beam consolidation system. The whole main beam 0# block includes the lower beam of the main tower and the π beam cantilever in the direction of large and small mileage. This construction 0# block is completed together with section 20 of the tower column. The lower beam of the main tower adopts a single box and single chamber section, and the top surface is a 2% two-way cross slope. The beam at the center of the box section is 6.28m high, 30.063m wide in the transverse direction and 6.0m wide along the bridge direction; The center of π beam is 2.98M high, the transverse width is 28.5m, and the length of unilateral cantilever is 5.5m.

Through several demonstration and disclosure, the project team successfully put the high-altitude cantilever support of the lower beam into practice, solved the problem that the lower beam is high from the ground and can not be constructed with floor support, so that the cantilever π beams on both sides can be completed stably; According to the structural form of 0# block, concrete block, water bag, steel bar, section steel, etc. are used for support preloading to observe settlement and eliminate inelastic deformation. In formal pouring, the measurement department and a third-party monitoring unit are also used for joint monitoring and real-time observation; By optimizing the mix proportion of polypropylene fiber concrete, the fluidity state of concrete is the best, and the construction problems such as easy pipe blockage in high tower pumping of mass concrete are avoided.

Considering the follow-up construction of the main bridge, the project department made a reasonable layout and planning for the embedded parts of the bridge deck construction in advance, including the reserved holes and thrust blocks of the hanging basket, the reserved holes and embedded steel plates of the winch, the embedded steel plates of the bridge deck elevator, the embedded steel plates of the inspection car track, etc., which provided convenience for the next process such as the removal of the main beam, elevator and lower beam support.

The successful pouring of z2# main tower 0# block broke through the most difficult link in the construction of Gaolingtou water reservoir bridge, successfully completed the construction of section 20 of the main tower, opened the prelude to the construction of the upper tower column, provided a key platform for the construction of the upper tower column, and accumulated valuable experience for the subsequent main beam construction of z1# main tower.