Construction site of Dongjiang Grand Bridge
At 6 a.m. on April 21, with the completion of the pouring of the last concrete, the Dongjiang Bridge of the Huihe Expressway Reconstruction and Expansion Project successfully realized the mid-span closure. From the air, the Dongjiang Bridge is like a giant dragon across both sides of the Dongjiang River, laying a solid foundation for the two-way eight-lane traffic opening of the whole line.
The Dongjiang Grand Bridge is one of the control projects of Huihe Expressway, with a total length of about 800 meters. The main bridge is a continuous steel structure, which adopts the method of unilateral widening, and is gradually poured in 18 sections through hanging basket suspension pouring construction. The bridge is located in a complex hydrogeological environment and adjacent to the existing high-speed railways. The bearing platform is buried 20 meters deep in the steep slope hard rock, and the heaviest section of the cantilever beam is 438.7 tons, equivalent to the weight of 220 cars. To ensure the construction safety, quality and progress at the same time, the construction faces many technical challenges.
The project team optimized the construction process, repeatedly deduced the process, innovated the construction method, established a stable and closed enclosure structure in the water, and solved the problem of underwater bearing platform construction in complex environments. The construction team used a fully enclosed hanging basket to avoid falling objects from the air and the impact of wind and rain. At the same time, the hanging basket is equipped with 12 high-precision sensors to monitor the force changes in real time, so as to accurately control the construction parameters, effectively improve the construction quality and efficiency, and compress the construction period of a single section from 15 days to 12 days.
In addition to ensuring the smooth progress of construction, the project team also actively implemented a number of green environmental protection measures to minimize the impact of construction. For example, the use of hanging baskets, the set-up of floats and warning boats on the water surface and deployment of dense engineering protective nets all proved to work efficiently. Drainage ditches and sedimentation tanks are built in the construction site to treat waste residue water and to avoid polluting the surrounding waters.
The mid-span closure of Dongjiang Grand Bridge has created good conditions for the construction of the pavement, and the follow-up constructions are to speed up the asphalt paving and traffic conversion of the pavement, and strive to achieve the goal of main line traffic opening as soon as possible.
As a strategic pilot infrastructure project of Guangdong Province, the Huihe Expressway Reconstruction and Expansion Project has a length of about 116.6 kilometers long, starting from Dongyuan County, Heyuan City, and ending in Huiyang District, Huizhou City. The two-way eight-lane expressway is expected to be completed and open to traffic by the end of this year.
Reported by DAI Jian, XIE Wenmin, QIAN Xiao’an, LU Jiatian
