KUNMING, Aug. 21 (Xinhua) The first precast box girder of the Qiubei No. 1 Bridge on the Qiuyan Expressway has been successfully installed, marking the transition of the project's bridge construction from substructure to superstructure, according to the China Railway 25th Bureau Group Co., Ltd. on Friday.
The Qiuyan Expressway, located in Wenshan Prefecture, Yunnan Province, has a total length of 63.78 km. Constructed as a two-way four-lane highway with a design speed of 100 km/h, it serves as a backbone route in the regional highway network.
In the deep karst mountains, the project team introduced 5G technology to upgrade the traditional beam yard into a "smart factory." The yard is tasked with producing 540 small box girders and 340 T-girders. Through a 5G-enabled smart control center, rebar processing is precisely managed by computerized numerical control systems, with errors reduced to the millimeter level. Smart variable-frequency vibrators installed on the formwork automatically adjust vibration timing and intensity based on concrete flow conditions, preventing quality defects such as honeycombing and surface voids. After the girders take shape, an automated intelligent tensioning and grouting system — controlled by computer and recording real-time data — eliminates human error and ensures structural safety.
"On the erection site, the high bandwidth and low latency of 5G have given the giant girder-launching machine a pair of 'clairvoyant eyes,'" said Yang Tao, head of the beam yard of China Railway 25th Bureau. "Through high-definition video and sensor data transmitted via 5G, every movement of the launching machine — hoisting, longitudinal moving, and transverse shifting — can be responded to within milliseconds. Engineers at the control center can monitor the girder's spatial posture and stress conditions in real time."
With the successful installation of the first girder, the superstructure construction of the Qiuyan Expressway's Section 1 has been fully launched. Leveraging 5G smart construction technologies, the builders are seizing the optimal construction period to overcome challenges such as high slopes and long tunnels, striving to open the expressway as soon as possible. Upon completion, the project will end Qiubei County's history of being without expressway access, significantly improving local travel conditions through connections with arterial routes like the G80 Guangzhou–Kunming Expressway, and boosting economic and trade exchanges between southeastern Yunnan and neighboring regions.
