Recently, after 938 days and nights of arduous work, the mainline bridge of the Junzhuang Interchange, constructed by the First Work Zone of the China Railway G109 Expressway General Contracting Department (built by China Railway First Group Second Company), was successfully closed, marking the completion of the bridge's main structure and laying a solid foundation for ensuring the project is completed and opened to traffic on schedule. As of now, 88% of the construction and installation work for the entire expressway has been completed, and bridge and tunnel construction are progressing steadily.

Backed by surrounding mountains, the Junzhuang Bridge on the new G109 Expressway under construction is just one step away from successfully spanning the Yongding River. At around 10 a.m. yesterday, on the bridge deck between the east and west spans of the Junzhuang mainline bridge, several workers were pouring concrete for the last approximately two meters of the bridge deck. With the completion of this section of deck construction, the Junzhuang Bridge was successfully closed.

The pouring of the pile cap for Pier No. 1 of the Junzhuang Interchange mainline bridge involved continuous mass concrete pouring. Mass concrete construction requires long pouring times and high work intensity. After pouring is completed, the heat dissipation conditions inside and on the surface of the concrete differ, forming a temperature gradient that easily produces thermal cracks. "The project effectively reduced the hydration heat of the mass concrete and adjusted the temperature difference between the inside and outside by covering the concrete exterior with geotextile, storing water on the surface, and other effective measures. Over the course of a year, the major milestone of pile cap pouring was completed," introduced Tian Gang, manager of the First Work Zone of the China Railway General Contracting Department for the new G109 Expressway.

The Junzhuang Interchange mainline bridge, constructed by China Railway First Group Second Company, is one of the key control projects of the entire line. It is the first of the three major bridges crossing the Yongding River on the new G109 Expressway project. Its main span crosses the Yongding River and S209 Shidan Road. The bridge has a total length of 789 meters and a design speed of 80 km/h. The main span is designed as a continuous rigid-frame structure, with a transverse deck width of 23.7 meters. Its continuous rigid-frame span is the longest among similar bridges in Beijing.

After the completion of the main structure of the Junzhuang mainline bridge, the next steps will include bridge deck paving, installation of crash barriers, and installation of sound barriers. "The Junzhuang Interchange mainline bridge of the new G109 Expressway crosses the Yongding River, with a maximum span reaching 188 meters. Once completed, it will become a beautiful scenic line along the Yongding River," introduced Song Kai, general manager of the China Railway and China Railway Investment G109 General Contracting Department.

The Junzhuang Bridge is one of the control projects of the new G109 Expressway. At present, the entire line's construction is progressing smoothly. Including the just-completed Junzhuang Bridge, 35 of the 36 bridges along the entire line have been completed; among the 16 tunnels, 12 have been holed through in both directions.