Recently, at the construction site of the Changshangkou Grand Bridge in Bid Section 1 of the Wuhan-Yichang section of the Shanghai-Chongqing Expressway in Xijiang Township, Hanchuan City, Xiaogan City, machinery roared, traffic flowed on the right side, and the on-site "4-to-8" lane expansion was in full swing.

The Wuhan-Yichang section of the Shanghai-Chongqing Expressway reconstruction and expansion project, Bid Section 1, undertaken by Hubei Jiaotou Construction Group, is 53.6 kilometers long and involves three areas: Caidian in Wuhan, Hanchuan in Xiaogan, and Xiantao.

Walking into the construction site of the Changshangkou Grand Bridge, a Jimu News reporter saw worker Master Liu using a hydraulic pile driver over 20 meters high to slowly "insert" a one-time formed precast pipe pile with a diameter of 1 meter and a length of about 20 meters from top to bottom into the ground thirty to forty meters deep.

On soft roadbed, why not carry out roadbed filling, but instead use pipe pile construction?

Luo Yong, project manager of the project at Hubei Jiaotou Construction Group, introduced that the soft foundation along the bid section is deep, and the Jianghan Plain area faces a shortage of soil. In order to give the soft foundation sections a "strong support" during the reconstruction and expansion construction and effectively avoid the risk of differential settlement of the lanes built in the future, two pipe pile column-type bridges were specially built along the route, with a total length of 10.6 kilometers and a total of 2,216 pipe piles.

Unlike ordinary pile foundations, these pipe piles are 1 meter in diameter, about 20 meters long, and weigh 1 ton. They are first prefabricated in factories and then transported to the construction site. During construction, there is no mud, and damage to the surface along the route can be reduced.

"Hoist slowly, ensure safety." Dong Daliang, the on-site construction manager, repeatedly reminded his coworkers not far from the crane. "Taking advantage of the recent fine weather, the bid section has 12 hydraulic pile drivers every day, and about 20 piles can be driven each day."

As the pipe piles continue to sink, how can it be ensured that they are driven accurately into the ground? Luo Yong told the Jimu News reporter that the project has enabled a pipe pile hammering monitoring system, relying on sensors to collect key parameters such as hammer blows and verticality in real time, achieving "cloud monitoring" of 2,216 pipe piles. The quality data of each pile is traceable, and the entire construction process is controlled. The project innovatively adopts a "four-column, pile-column integrated" design. By adding new fiber materials and optimizing the joint process, the stability of the pile foundation in soft soil has been greatly improved, and the bearing capacity has increased by 30% compared with traditional bored cast-in-place piles.

The Jimu News reporter learned that this is the first large-scale expressway pipe pile column-type bridge construction case in the country. At present, 1,216 pipe piles have been completed in the bid section, and all tasks are planned to be completed in July this year, winning time for subsequent bridge construction.

After the project is completed, it will comprehensively upgrade the traffic capacity of the national expressway corridor, densify Hubei's comprehensive transportation network of "three hubs, two corridors, three regions, and nine channels," and the existing Han-Yi Expressway will become eight lanes in both directions, building a "fast lane" for coordinated development between the Wuhan metropolitan area and the Yijing-Jing metropolitan area.

Source: Chutian Metropolis Daily