WORLD'S LARGEST 3D-PRINTED BRIDGE

The world’s largest pedestrian bridge 3D-printed entirely in concrete has been completed in the industrial and creative centre of the Baoshan District of Shanghai. The project was designed and fabricated by a team led by professor Xu Weiguo of Tsinghua University’s School Of Architecture, Zoina Land Joint Research Centre for Digital Architecture (JCDA) together with Shanghai wisdom bay investment management company.

The 3D-printed bridge spans 26.3 metres with a width of 3.6 metres. In the development of the structure, the design team took precedent from the ancient Anji Bridge — the world’s oldest open-spandrel, stone segmental arch bridge — in Zhaoxian, China.

Before Tsinghua University’s team, JCDA underwent the printing of the bridge at full scale, a 1:4 scale physical model was built to carry out the structure failure testing. This served to prove the bridge’s strength can meet the maximum live load requirements of pedestrians crowding the bridge. The fabrication of the bridge comprises a 3D printing concrete system independently developed by professor Xu Weiguo’s team.

The system integrates such technologies as digital architectural design, printing path generation, operation control system, and state of the art printing tools. The concrete components of this bridge had been entirely printed with two robotic arm 3D printing systems over the course of 450 hours.

The bridge is characterized by high printing efficiency, high moulding precision and high constancy in prolonged work. There are three main innovation points of the system that are taking the leading position in the field internationally. The first is the printing tool of the robot arm, which avoids a plugging in the extrusion process and collapse during the stacking of material layers. For the path generation and operating system, the process integrates form design, material pumping, robot arm movement along with other systems working simultaneously. The third point is a unique printing material formula, which has reasonable performance and stable rheology, or material flow.

The design of the pedestrian bridge adopts three-dimensional solid modelling. The bridge handrails are shaped like flowing ribbons on the arch, forming a light and elegant posture lying on the pond of shanghai wisdom bay. The pavements of the bridge are generated from the form of brain corals, and white pebbles are filled in the voids of the pattern.

The bridge is embedded with real-time monitoring system, including vibrating wire stress sensors and high-precision strain monitoring system, which can collect the force and deformation data of the bridge in real time. They will have a practical effect on tracking the performance of new concrete materials and the structural mechanical properties of printing components.

Via Designboom | Images courtesy of JCDA