The first bridge of Chongqing railway wall copper line project is completed

On September 15, with the completion of the pouring of the last piece of box girder, the four bridges of the three bid sections of Chongqing railway wall copper line and the six branch sections of the hkust section, which were constructed by the group, were successfully completed, becoming the first bridge with more than 10 spans to be completed in the wall copper line project.

The Chongqing Railway Wall Copper Line Project is the urban express rail from Chongqing Bishan Station to Tongliang Station. It is an important line for the integrated development of rail transit in the main city metropolitan area. The line has a total length of 37.5 kilometers and 9 stations. The group undertakes part of the engineering construction tasks, and the line is about 7.3 kilometers long, including 11 bridges and 11 sections of subgrade. After the completion of the project, it will further serve the people's livelihood and promote economic and cultural exchanges between Chongqing and various districts.

Section 4 Bridge is located between Kechuang Xincheng Station and Dalu Station. The bridge is 450 meters long. This section covers 61 pile foundations, 15 caps, 15 piers and 14 box girders. Since the foundation construction of bored piles was officially carried out on October 28, 2021, the urban construction northern project management team has focused on epidemic prevention and control and construction production on the one hand, and adhered to the "safety is the sky, quality is the first, management is the first, and the construction period is the first." The requirements of ", strictly complete each process, and go all out to promote the construction of the project.

The construction area is rich in groundwater resources, and the holding stratum is dominated by weathered mudstone, with poor geological conditions. During the construction of bridge pile foundation, it is difficult to form holes in flood season, which is easy to cause the sediment at the bottom of the hole to exceed the standard. The project team combined with the actual site, the groundwater-rich areas using full-tube bored pile construction, pile foundation construction in a timely manner to pump water, pile foundation perfusion using high-performance underwater concrete, to ensure the quality of pile foundation construction.

The high temperature and long duration in summer in Chongqing area have a great impact on the operation of migrant workers and the maintenance of structural entities. The project department adjusted the operation time to take 6: 00 a.m. to 10: 00 a.m. and 18: 00 p.m. to 21: 00 p.m. as the main working time to ensure personal safety and prevent heatstroke. For pier columns, box girders and other structural entities, after pouring, they are covered with plastic film and geotextile, and sprinkled regularly every day by sprinklers to ensure full maintenance of structural entities.

The main body of the bridge is a curved bridge, and the structure of the box girder is complex, there are many special parts such as chamfering, bending and so on. After many discussions by the team, the combination form of "steel formwork and wood formwork" was finally determined for box girder construction. Among them, clear water wood formwork is used for plane parts such as bottom plate, wing plate and web plate, and shaped steel formwork is used for bending arc and chamfer to ensure the forming quality and appearance of the main body.

The project team completed the pouring of the first pile cap on November 22, 2021. On December 23, 2021, the pouring construction of the first pier column will be completed. On April 2, 2022, the pouring of the first box girder will be completed. After 10 months of unremitting struggle, the construction task of the main structure of the bridge was finally completed on September 15.

In the following construction, the project management team sounded the "charge" horn for the construction of Qinglonghu Station on the wall copper line and the five bridges under its jurisdiction to ensure the completion of the set goals with high quality and efficiency.