Chongqing - On December 6, Chongqing Expressway Juneng Construction Group achieved a significant milestone by deploying unmanned, autonomous paving technology in the Dingjia Tunnel, a critical segment of the Wuxi-Yunyang-Kaizhou Expressway. 

This marked the first use of such technology in Chongqing, successfully addressing challenges like the lack of satellite signals in long tunnels. The achievement demonstrates that unmanned paving can now be effectively utilized for roads, bridges, and tunnel pavements in mountainous highway projects.

The Wuxi-Yunyang-Kaizhou Expressway, spanning 118.62 kilometers from Wuxi to Yunyang to Kaizhou, features a 61% bridge-to-tunnel ratio, reflecting the extreme difficulty of constructing highways in mountainous regions. The unmanned paving operation was conducted on the 4,176-meter-long Dingjia Tunnel’s right lane in Yunyang County.

The unmanned paver is currently operating in the tunnel. (Photo/Chongqing Expressway Juneng Construction Group)

Addressing the technical challenges, the project leader explained that the precision required for unmanned paving is exceptionally high, particularly in tunnels where satellite signals are unavailable. 

To tackle these obstacles, the technical team at Chongqing Expressway Juneng Construction Group equipped the machinery with advanced sensors akin to “eyes” and “ears” to enable autonomous operation. They developed a system combining SLAM LiDAR and RTK positioning algorithms, integrating radar scanning with BeiDou navigation for accurate positioning. Smart sensing, fusion computing, and collaborative tasking ensured seamless and stable operations, enabling precise control of the paving process.

Additionally, the team digitized construction blueprints, transforming them into 3D models to create a detailed compaction grid. This approach enhanced pavement quality and density, achieving a 100% pass rate in compactness tests. Safety was also prioritized by developing multi-sensor fusion collision-avoidance technology, ensuring secure equipment operations, and advancing construction standards.

Since last year, Chongqing Expressway Juneng Construction Group has successfully conducted unmanned paving operations on several projects, including the Liangping-Kaijiang Expressway and the new expressway linking Chongqing and Changsha.

Its efforts are part of Chongqing’s pilot program for intelligent highway construction, which has been recognized as a leading initiative by the Ministry of Transport of the PRC and listed as a key project for Chongqing's state-owned enterprises. This latest success in long-tunnel paving further solidifies Chongqing’s position as a pioneer in smart highway construction in mountainous regions.