Innovative bridge-construction solutions adopted on the Loop project in Hong Kong

The Loop is a major infrastructure project improving transport access to a new innovation and technology park near the Hong Kong–Shenzhen boundary in China. It features two vehicular viaducts – Bridge ST01 and Bridge DRL – each comprising multiple spans of prestressed concrete box-girder decks, built in highly constrained areas near existing highways and railways. For Bridge ST01, five spans were installed using an innovative full-span erection approach, which uniquely comprised three principal activities: on-site pre-assembly of precast segments into full-span units, transportation of these units to erection fronts using self-propelled modular transporters and lifting to their final position by way of strand-jacking frames. Although each activity had been used individually before, this project’s innovation lay in integrating all three into a single coordinated operation. For Bridge DRL, deck erection was accomplished through the balanced-cantilever method employing a bespoke special lifting frame equipped with a rotational turntable, enabling multiple functions to be efficiently performed, including lifting segments from any orientation, transporting them to the tip of the balanced-cantilever deck and placing them in their final position. These solutions, tailored for this project’s specific constraints, improved safety and productivity while also reducing impacts on the surrounding environment.